Heat load processing system

ABSTRACT

Provided is a measure against a refrigerant leak. A heat load processing system has a plurality of refrigerant circuits and includes a plurality of device units, a casing that collectively houses the plurality of device units configuring the different refrigerant circuits, a refrigerant leak detector that individually detects a refrigerant leak in the respective refrigerant circuits, and a controller. The device units include a heat exchanger that is connected to a refrigerant pipe and a heat medium pipe as a device configuring one of the refrigerant circuits. When the refrigerant leak detector detects the refrigerant leak, the controller performs refrigerant leaking circuit identification processing for identifying a refrigerant circuit in which the refrigerant leak is occurring and a refrigerant leak third control for changing an operating state of a predetermined refrigerant circuit based on a result of the refrigerant leaking circuit identification processing.

TECHNICAL FIELD

The present disclosure relates to a heat load processing system.

BACKGROUND ART

Conventionally, as disclosed in Patent Literature 1 (JP 2006-38323 A),there are known refrigerant system component devices configuring arefrigerant system including a compressor and a heat exchanger that isconnected to a refrigerant pipe through which refrigerant flows and aheat medium pipe through which heat medium flows to cause therefrigerant and the heat medium to exchange heat with each other.

SUMMARY OF THE INVENTION Technical Problem

Refrigerant system component devices may suffer from a refrigerant leakdue to damage to, degradation over time of, or poor connection of arefrigerant pipe, a heat exchanger, and the like. On the other hand, ina heat load processing system including a plurality of refrigerantsystems, quick identification of a refrigerant system in which arefrigerant leak is occurring is desired.

Solutions to Problem

A heat load processing system according to a first aspect is a heat loadprocessing system having a plurality of refrigerant systems throughwhich refrigerant circulates and includes a plurality of refrigerantsystem component devices, a casing, a refrigerant leak detection unit,and a control unit. The refrigerant system component devices include acompressor and/or a heat exchanger as (a) device(s) forming one of therefrigerant systems. The compressor compresses the refrigerant. The heatexchanger is connected to a refrigerant pipe and a heat medium pipe. Therefrigerant pipe is a pipe through which the refrigerant flows. The heatmedium pipe is a pipe through which heat medium flows. The heatexchanger causes the refrigerant and the heat medium to exchange heatwith each other. The casing collectively houses the plurality ofrefrigerant system component devices. The refrigerant leak detectionunit individually detects a refrigerant leak in the respectiverefrigerant systems. The control unit controls operations of actuatorsof the respective refrigerant systems. When the refrigerant leakdetection unit detects the refrigerant leak, the control unit performsfirst processing and second processing. The first processing isprocessing for identifying a refrigerant leaking system that is therefrigerant system in which the refrigerant leak is occurring. Thesecond processing is processing for changing an operating state of atleast one of the refrigerant systems based on a result of the firstprocessing.

Thus, in the heat load processing system including the plurality ofrefrigerant systems, it is possible to quickly identify the refrigerantsystem in which the refrigerant leak is occurring. Moreover, it ispossible to change the operating state of the predetermined refrigerantsystem in accordance with the identification result.

The “refrigerant leak detection unit” is a refrigerant leak sensor fordirectly detecting the refrigerant that is leaking (leakingrefrigerant), a pressure sensor or a temperature sensor for detectingstates (a pressure or a temperature) of the refrigerant in therefrigerant system, and/or a computer that determines presence orabsence of the refrigerant leak based on detection values of thesensors.

A heat load processing system according to a second aspect is the heatload processing system according to the first aspect, in which thecontrol unit controls the refrigerant leaking system into a stop statein the second processing. This reduces the further refrigerant leak fromthe refrigerant leaking system when the refrigerant leak occurs.

A heat load processing system according to a third aspect is the heatload processing system according to the first or second aspect furtherincluding a refrigerant state sensor. The refrigerant state sensordetects pressures or temperatures of the refrigerant in the respectiverefrigerant systems. The control unit identifies the refrigerant leakingsystem by comparing states of the refrigerant in the respectiverefrigerant systems with each other based on detection values of therefrigerant state sensor. This makes it easy to discharge the leakingrefrigerant from a facility device room to the other space when therefrigerant leak occurs in the heat exchanger unit.

A heat load processing system according to a fourth aspect is the heatload processing system according to any one of the first to thirdaspects, in which the control unit identifies the refrigerant leakingsystem while operating the respective refrigerant systems in the firstprocessing.

A heat load processing system according to a fifth aspect is the heatload processing system according to any one of the first to thirdaspects, in which the control unit identifies the refrigerant leakingsystem while stopping the respective refrigerant systems in the firstprocessing.

A heat load processing system according to a sixth aspect is the heatload processing system according to the fifth aspect, in which therefrigerant system component devices further include a second heatexchanger. The second heat exchanger causes the refrigerant compressedby the compressor to condense or radiate heat by causing the refrigerantto exchange heat with water. The control unit identifies the refrigerantleaking system based on a degree of a pressure drop of the high-pressurerefrigerant in each of the refrigerant systems in the first processing.This makes it easy to identify the refrigerant leaking system when therefrigerant system component devices include the second heat exchangerthat causes the high-pressure refrigerant to condense or radiate heat bycausing the refrigerant to exchange heat with the water.

A heat load processing system according to a seventh aspect is the heatload processing system according to any one of the first to sixthaspects, in which the control unit controls the refrigerant systems,other than the refrigerant leaking system out of the refrigerant systemsoperating when the refrigerant leak is detected by the refrigerant leakdetection unit, in operating states, in the second processing. Thus, therefrigerant systems in which no refrigerant leak is occurring cancontinue operating.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram of a heat load processingsystem.

FIG. 2 is a diagrammatic illustration showing a concrete example ofrefrigerant used in refrigerant circuit.

FIG. 3 is a diagrammatic illustration showing a manner of installationof the heat load processing system.

FIG. 4 is a schematic plan view of a facility device room in which aheat exchanger unit is installed.

FIG. 5 is a perspective view of the heat exchanger unit.

FIG. 6 is a diagrammatic illustration showing a manner of disposition ofdevices in a casing in a plan view.

FIG. 7 is a diagrammatic illustration showing the manner of dispositionof the devices in the casing in a side view.

FIG. 8 is a diagrammatic illustration showing the manner of dispositionof the devices in the casing in a front view.

FIG. 9 is a diagrammatic illustration of a bottom plate in a plan view.

FIG. 10 is a diagrammatic illustration of the bottom plate in a sideview.

FIG. 11 is a diagrammatic illustration schematically showing a manner ofdisposition of an exhaust fan unit and a cooling fan in the casing.

FIG. 12 is a block diagram schematically showing a controller andcomponents connected to the controller.

FIG. 13 is a flowchart of exemplary processing to be performed by thecontroller.

FIG. 14 is a perspective view of a heat exchanger unit according toModification 1.

FIG. 15 is a diagrammatic illustration showing a manner of dispositionof devices in the heat exchanger unit according to Modification 1 in aplan view.

FIG. 16 is a diagrammatic illustration showing the manner of dispositionof the devices in the heat exchanger unit according to Modification 1 ina front view.

FIG. 17 is a diagrammatic illustration showing the manner of dispositionof the devices in the heat exchanger unit according to Modification 1 ina side view.

FIG. 18 is a diagrammatic illustration schematically showing a manner ofconfiguration of a heat load processing system according to Modification1.

DESCRIPTION OF EMBODIMENTS

With reference to the drawings, a heat load processing system 100according to an embodiment of the present disclosure will be describedbelow. Note that the following embodiment is merely a specific exampleof the present disclosure and does not intend to limit the technicalscope of the present disclosure. The embodiment can be changed asappropriate without departing from the gist of the present disclosure.The following description may include expressions such as “up”, “down”,“left”, “right”, “front (front side)”, and “rear (rear side)” indicatingdirections. Unless otherwise specified, these directions indicatedirections shown by arrows in the figures. Note that these expressionsrelated to the directions are used merely to facilitate understanding ofthe embodiment and do not intend to limit the ideas according to thepresent disclosure.

(1) Heat Load Processing System 100

FIG. 1 is a schematic configuration diagram of a heat load processingsystem 100. The heat load processing system 100 is a system forprocessing a heat load in an installation environment. In theembodiment, the heat load processing system 100 is an air conditioningsystem that performs air conditioning of a target space.

The heat load processing system 100 mainly includes a plurality of(here, four) heat-source-side units 10, a heat exchanger unit 30, aplurality of (here, four) use-side units 60, a plurality of (here, four)liquid-side connection pipes LP, a plurality of (here, four) gas-sideconnection pipes GP, a first heat medium connection pipe H1 and a secondheat medium connection pipe H2, a refrigerant leak sensor 70, and acontroller 80 that controls an operation of the heat load processingsystem 100.

In the heat load processing system 100, the heat-source-side units 10and the heat exchanger unit 30 are connected to each other via theliquid-side connection pipes LP and the gas-side connection pipes GP tothereby form refrigerant circuits RC through which refrigerantcirculates. In the heat load processing system 100, in relation to thefact that the plurality of heat-source-side units 10 are arranged inparallel, the plurality of (here, four) refrigerant circuits RC(refrigerant system) are formed. In other words, in the heat loadprocessing system 100, the plurality of heat-source-side units 10 andthe heat exchanger unit 30 form the plurality of refrigerant circuitsRC. The heat load processing system 100 performs a vapor compressionrefrigeration cycle in each of the refrigerant circuits RC.

In the embodiment, the refrigerant filled into the refrigerant circuitsRC is a flammable refrigerant. Here, the flammable refrigerant includesrefrigerants falling into Class 3 (higher flammability), Class 2(Flammable), and Sub class 2L (Lower flammability) in accordance withthe United States ASHRAE 34 Designation and safety classification ofrefrigerant or ISO 817 Refrigerants-Designation and safetyclassification. For example, specific examples of the refrigerant usedin the embodiment are shown in FIG. 2. In FIG. 2, “ASHRAE Number”represents ASHRAE number of the refrigerant specified in ISO 817,“Composition” represents ASHRAE number of substances included in therefrigerant, “Mass %” represents percent concentrations of mass ofrespective substances included in the refrigerant, and “Alternative”represents a name of a substance often replaced by the refrigerant. Therefrigerant used specifically in the embodiment is R32. The refrigerantfilled into the refrigerant circuits RC may be a refrigerant notillustrated in FIG. 2 and may be a CO₂ refrigerant or a refrigerant suchas ammonia having toxicity, for example. The refrigerants filled intothe respective refrigerant circuits RC do not necessarily have to be thesame refrigerants.

In the heat load processing system 100, the heat exchanger unit 30 andeach of the use-side units 60 are connected to each other via the firstheat medium connection pipe H1 and the second heat medium connectionpipe H2 to thereby form a heat medium circuit HC through which heatmedium circulates. In other words, in the heat load processing system100, the heat exchanger unit 30 and each of the use-side units 60 formthe heat medium circuit HC. In the heat medium circuit HC, a pump 36(described later) of the heat exchanger unit 30 is driven to therebycirculate the heat medium.

In the embodiment, the heat medium filled into the heat medium circuitHC is liquid medium such as water and brine, for example. Examples ofthe brine include an aqueous solution of sodium chloride, an aqueoussolution of calcium chloride, an aqueous solution of ethylene glycol,and an aqueous solution of propylene glycol. The liquid medium is notlimited to those kinds mentioned here as the examples and it is possibleto select a suitable kind of liquid medium. The brine is used as theheat medium specifically in the embodiment.

(2) Detailed Configurations

(2-1) Heat-Source-Side Unit 10

In the embodiment, the heat load processing system 100 has the fourheat-source-side units 10 (see FIG. 1). The heat exchanger unit 30 coolsor heats the liquid medium with the refrigerant cooled or heated in thefour heat-source-side units 10. Note that the number of heat-source-sideunits 10 is merely an example and the number is not limited to four.There may be provided one to three or five or more heat-source-sideunit(s) 10. FIG. 1 illustrates an internal configuration of only one ofthe four heat-source-side units 10 and does not illustrate internalconfigurations of the other three heat-source-side units 10. Theheat-source-side units 10 not illustrated in the figure have similarconfigurations to the heat-source-side unit 10 described below.

The heat-source-side units 10 are units that cool or heat therefrigerant by using air as a heat source. Each of the heat-source-sideunits 10 is individually connected to the heat exchanger unit 30 via theliquid-side connection pipe LP and the gas-side connection pipe GP. Inother words, each of the respective heat-source-side units 10individually forms the refrigerant circuit RC (refrigerant system)together with the heat exchanger unit 30. In other words, in the heatload processing system 100, the plurality of (here, four)heat-source-side units 10 are respectively connected to the heatexchanger unit 30 to thereby form the plurality of (here, four)refrigerant circuits RC (refrigerant systems). Note that the respectiverefrigerant circuits RC are separated from each other and notcommunicating with each other.

An installation place of each of the heat-source-side units 10 is notlimited and may be a space on a rooftop or around a building, forexample. Each of the heat-source side units 10 is connected to the heatexchanger unit 30 via the liquid-side connection pipe LP and thegas-side connection pipe GP and forms a part of the refrigerant circuitRC.

Each of the heat-source-side units 10 mainly includes, as devicesforming the refrigerant circuit RC, a plurality of refrigerant pipes (afirst pipe P1 to an eleventh pipe P11), a compressor 11, an accumulator12, a four-way switching valve 13, a heat-source-side heat exchanger 14,a subcooler 15, a heat-source-side first control valve 16, aheat-source-side second control valve 17, a liquid-side shutoff valve18, and a gas-side shutoff valve 19.

The first pipe P1 connects the gas-side shutoff valve 19 and a firstport of the four-way switching valve 13. The second pipe P2 connects aninlet port of the accumulator 12 and a second port of the four-wayswitching valve 13. The third pipe P3 connects an outlet port of theaccumulator 12 and an intake port of the compressor 11. The fourth pipeP4 connects a discharge port of the compressor 11 and a third port ofthe four-way switching valve 13. The fifth pipe P5 connects a fourthport of the four-way switching valve 13 and a gas-side inlet/outlet ofthe heat-source-side heat exchanger 14. The sixth pipe P6 connects aliquid-side inlet/outlet of the heat-source-side heat exchanger 14 andone end of the heat-source-side first control valve 16. The seventh pipeP7 connects the other end of the heat-source-side first control valve 16and one end of a main flow path 151 of the subcooler 15. The eighth pipeP8 connects the other end of the main flow path 151 of the subcooler 15and one end of the liquid-side shutoff valve 18.

The ninth pipe P9 connects a portion between opposite ends of the sixthpipe P6 and one end of the heat-source-side second control valve 17. Thetenth pipe P10 connects the other end of the heat-source-side secondcontrol valve 17 and one end of a sub flow path 152 of the subcooler 15.The eleventh pipe P11 connects the other end of the sub flow path 152 ofthe subcooler 15 and an injection port of the compressor 11.

Actually, each of the refrigerant pipes (P1 to P11) may include a singlepipe or a plurality of pipes connected to each other via joints or thelike.

The compressor 11 is a device that compresses low-pressure refrigerantuntil the refrigerant turns into high-pressure refrigerant in therefrigeration cycle. The compressor 11 used in this embodiment is aclosed compressor in which a compression element of a displacement type,such as rotary type or scroll type, is driven to rotate by a compressormotor (not illustrated). An inverter can control an operating frequencyof the compressor motor. In other words, the compressor 11 has acontrollable capacity. However, the compressor 11 may be a fixedcapacity compressor.

The accumulator 12 is a container for suppressing excessive suction ofthe liquid refrigerant into the compressor 11. The accumulator 12 has apredetermined capacity depending on an amount of refrigerant filled inthe refrigerant circuit RC.

The four-way switching valve 13 is a flow path switching mechanism forchanging a flow of the refrigerant in the refrigerant circuit RC. Thefour-way switching valve 13 is switchable between a forward cycle stateand a reverse cycle state. The four-way switching valve 13, in theforward cycle state, communicates between the first port (the first pipeP1) and the second port (the second pipe P2) and communicates betweenthe third port (the fourth pipe P4) and the fourth port (the fifth pipeP5) (see solid lines in the four-way switching valve 13 in FIG. 1). Thefour-way switching valve 13, in the reverse cycle state, communicatesbetween the first port (the first pipe P1) and the third port (thefourth pipe P4) and communicates between the second port (the secondpipe P2) and the fourth port (the fifth pipe P5) (see broken lines inthe four-way switching valve 13 in FIG. 1).

The heat-source-side heat exchanger 14 is a heat exchanger thatfunctions as a condenser (or a radiator) or an evaporator for therefrigerant. The heat-source-side heat exchanger 14 functions as thecondenser for the refrigerant during a forward cycle operation(operation with the four-way switching valve 13 in the forward cyclestate). On the other hand, the heat-source-side heat exchanger 14functions as the evaporator for the refrigerant during a reverse cycleoperation (operation with the four-way switching valve 13 in the reversecycle state). The heat-source-side heat exchanger 14 includes aplurality of heat transfer tubes and fins (not illustrated). The heatsource-side heat exchanger 14 is configured to cause the refrigerant inthe heat transfer tubes to exchange heat with air (a heat-source-sideair flow described later) passing around the heat transfer tubes or heattransfer fins.

The subcooler 15 is a heat exchanger that makes the incoming refrigerantinto liquid refrigerant in a subcooled state. The subcooler 15 is adouble-pipe heat exchanger, for example, and includes the main flow path151 and the sub flow path 152. The subcooler 15 is configured to causethe refrigerant flowing through the main flow path 151 and therefrigerant flowing through the sub flow path 152 to exchange heat witheach other.

The heat-source-side first control valve 16 is an electronic expansionvalve whose opening degree is controllable. By controlling the openingdegree, the heat-source-side first control valve 16 decompresses theincoming refrigerant or adjusts a flow rate of the incoming refrigerant.The heat-source-side first control valve 16 is switchable between anopen state and a closed state. The heat-source-side first control valve16 is disposed between the heat-source-side heat exchanger 14 and thesubcooler 15 (the main flow path 151).

The heat-source-side second control valve 17 is an electronic expansionvalve whose opening degree is controllable. By controlling the openingdegree, the heat-source-side second control valve 17 decompresses theincoming refrigerant or adjusts a flow rate of the incoming refrigerant.The heat-source-side second control valve 17 is switchable between anopen state and a closed state. The heat-source-side second control valve17 is disposed between the heat-source-side heat exchanger 14 and thesubcooler 15 (the sub flow path 152).

The liquid-side shutoff valve 18 is a manual valve disposed at a jointbetween the eighth pipe P8 and the liquid-side connection pipe LP. Theliquid-side shutoff valve 18 has the one end connected to the eighthpipe P8 and the other end connected to the liquid-side connection pipeLP.

The gas-side shutoff valve 19 is a manual valve disposed at a jointbetween the first pipe P1 and the gas-side connection pipe GP. Thegas-side shutoff valve 19 has the one end connected to the first pipe P1and the other end connected to the gas-side connection pipe GP.

Each of the heat-source-side units 10 has a heat-source-side fan 20 thatgenerates the heat-source-side air flow passing through theheat-source-side heat exchanger 14. The heat-source-side fan 20 is a fanconfigured to supply to the heat-source-side heat exchanger 14 theheat-source-side air flow for cooling or heating the refrigerant flowingthrough the heat-source-side heat exchanger 14. The heat-source-side fan20 includes a heat-source-side fan motor (not illustrated) that is adrive source and start and stop and the number of rotations of theheat-source-side fan 20 are appropriately controlled in accordance witha situation.

Each of the heat-source-side units 10 also includes a plurality ofheat-source-side sensors S1 (see FIG. 12) for detecting states (mainly,a pressure or a temperature) of the refrigerant in each of therefrigerant circuits RC. Each of the heat-source-side sensors S1(refrigerant state sensors) is a pressure sensor or a temperature sensorsuch as a thermistor or a thermocouple. The heat-source-side sensors S1include a first temperature sensor 21 that detects a temperature(suction temperature) of the refrigerant on a suction side (in the thirdpipe P3) of the compressor 11 or a second temperature sensor 22 thatdetects a temperature (discharge temperature) of the refrigerant on adischarge side (in the fourth pipe P4) of the compressor 11, forexample. The heat-source-side sensors S1 also include a thirdtemperature sensor 23 that detects a temperature of the refrigerant on aliquid side (in the sixth pipe P6) of the heat-source-side heatexchanger 14, a fourth temperature sensor 24 that detects a temperatureof the refrigerant in the eighth pipe P8, or a fifth temperature sensor25 that detects a temperature of the refrigerant in the eleventh pipeP11, for example. The heat-source-side sensors S1 also include a firstpressure sensor 27 that detects a pressure (suction pressure) of therefrigerant on the suction side (in the second pipe P2) of thecompressor 11 and a second pressure sensor 28 that detects a pressure(discharge pressure) of the refrigerant on the discharge side (in thefourth pipe P4) of the compressor 11, for example.

Each of the heat-source-side units 10 also has a heat-source-side unitcontrol unit 29 that controls operations and states of the respectivedevices included in the heat-source-side unit 10. The heat-source-sideunit control unit 29 includes, in order to perform its functions,various kinds of electric circuits, a microcomputer having amicroprocessor and a memory chip on which programs performed by themicroprocessor are stored, and the like. The heat-source-side unitcontrol unit 29 is electrically connected to the respective devices(e.g., the devices 11, 13, 16, 17, and 20) and the heat-source-sidesensors S1 included in the heat-source-side unit 10 to exchange signalswith the devices and the heat-source-side sensors S1. Theheat-source-side unit control unit 29 is electrically connected to aheat exchanger unit control unit 49 (described later) of the heatexchanger unit 30 or the like via a communication line to exchangecontrol signals with the heat exchanger unit control unit 49.

(2-2) Heat Exchanger Unit 30

The heat exchanger unit 30 is a device that performs at least one ofcooling and heating of the heat medium by causing the heat medium andthe refrigerant to exchange heat with each other. In the embodiment, theheat exchanger unit 30 causes the heat medium and the refrigerant toexchange heat with each other to thereby cool and heat the heat medium.The heat medium cooled or heated by the liquid refrigerant in the heatexchanger unit 30 is sent to the use-side units 60.

The heat exchanger unit 30 is a unit that cools or heats the heat mediumsent to the use-side units 60 by causing the heat medium and therefrigerant to exchange heat with each other. An installation place ofthe heat exchanger unit 30 is not limited and may be an interior spacesuch as a facility device room, for example. The heat exchanger unit 30includes, as devices forming the respective refrigerant circuits RC, thesame number of a plurality of (here, four) refrigerant pipes(refrigerant pipes Pa, Pb, Pc, Pd), expansion valves 31, and on-offvalves 32 as the heat-source-side units 10 (the refrigerant circuitsRC). The heat exchanger unit 30 also includes heat exchangers 33 asdevices forming the respective refrigerant circuits RC and the heatmedium circuit HC.

Each of the refrigerant pipes Pa connects the liquid-side connectionpipe LP and one end of the expansion valve 31. Each of the refrigerantpipes Pb connects the other end of the expansion valve 31 and aliquid-side refrigerant inlet/outlet of one of the heat exchangers 33.Each of the refrigerant pipes Pc connects a gas-side refrigerantinlet/outlet of one of the heat exchangers 33 and one end of the on-offvalve 32. Each of the refrigerant pipes Pd connects the other end of theon-off valve 32 and the gas-side connection pipe GP. Actually, each ofthe refrigerant pipes (Pa to Pd) may include a single pipe or aplurality of pipes connected to each other via joints or the like.

Each of the expansion valves 31 is an electronic expansion valve whoseopening degree is controllable. By controlling the opening degree, theexpansion valve 31 decompresses the incoming refrigerant or adjusts aflow rate of the incoming refrigerant. The expansion valve 31 isswitchable between an open state and a closed state. The expansion valve31 is disposed between the heat exchanger 33 and the liquid-sideconnection pipe LP.

Each of the on-off valves 32 is a control valve switchable between anopen state and a closed state. The on-off valve 32 interrupts therefrigerant in the closed state. The on-off valve 32 is disposed betweenthe heat exchanger 33 and the gas-side connection pipe GP.

A plurality of flow paths (refrigerant flow paths RP) for therefrigerant flowing through the refrigerant circuits RC are formed ineach of the heat exchangers 33. In the heat exchangers 33, each of therefrigerant flow paths RP does not communicate with the otherrefrigerant flow paths RP. In relation to this, in the heat exchangers33, the same number of (here, four) liquid-side inlets/outlets andgas-side inlets/outlets of the refrigerant flow paths RP as therefrigerant flow paths RP are formed. In the heat exchangers 33, flowpaths (heat medium flow paths HP) for the heat medium flowing throughthe heat medium circuit HC are formed.

To put it more concretely, the heat exchangers 33 include the first heatexchanger 34 and the second heat exchanger 35. The first heat exchanger34 and the second heat exchanger 35 are formed as separate bodies. Ineach of the first heat exchanger 34 and the second heat exchanger 35,the two separate refrigerant flow paths RP are formed. In each of thefirst heat exchanger 34 and the second heat exchanger 35, one end ofeach of the refrigerant flow paths RP is connected to the refrigerantpipe Pb of the corresponding refrigerant circuit RC and the other end ofeach of the refrigerant flow paths RP is connected to the refrigerantpipe Pc of the corresponding refrigerant circuit RC. In the first heatexchanger 34, one end of the heat medium flow path HP is connected to aheat medium pipe Hb (described later) and the other end of the heatmedium flow path HP is connected to a heat medium pipe Hc (describedlater). In the second heat exchanger 35, one end of the heat medium flowpath HP is connected to the pipe Hc (described later) and the other endof the heat medium flow path HP is connected to a heat medium pipe Hd(described later). The heat medium flow paths HP of the first heatexchanger 34 and the second heat exchanger 35 are arranged in series inthe heat medium circuit HC. The first heat exchanger 34 and the secondheat exchanger 35 are configured to cause the refrigerant flowingthrough the respective refrigerant flow paths RP (refrigerant circuitsRC) and the heat medium flowing through the heat medium flow paths HP(heat medium circuit HC) to exchange heat with each other.

The heat exchanger unit 30 also includes, as the devices forming theheat medium circuit HC, the plurality of heat medium pipes (heat mediumpipes Ha, Hb, Hc, Hd) and the pump 36.

The heat medium pipe Ha has one end connected to the first heat mediumconnection pipe H1 and the other end connected to a suction-side port ofthe pump 36. The heat medium pipe Hb has one end connected to adischarge-side port of the pump 36 and the other end connected to theone end of the heat medium flow path HP of the first heat exchanger 34.The heat medium pipe Hc has one end connected to the other end of theheat medium flow path HP of the first heat exchanger 34 and the otherend connected to the one end of the heat medium flow path HP of thesecond heat exchanger 35. The heat medium pipe Hd has one end connectedto the other end of the heat medium flow path HP of the second heatexchanger 35 and the other end connected to the second heat mediumconnection pipe H2. Actually, each of the heat medium pipes (Ha to Hd)may include a single pipe or a plurality of pipes connected to eachother via joints or the like.

The pump 36 is disposed in the heat medium circuit HC. The pump 36 drawsin and discharges the heat medium during operation. The pump 36 includesa motor that is a drive source and the motor is inverter controlled tothereby adjust the number of rotations of the pump 36. In other words,the pump 36 is a variable discharge flow rate pump. The heat exchangerunit 30 may include a plurality of pumps 36 connected in series orparallel in the heat medium circuit HC. The pump 36 may be a constantrate pump.

The heat exchanger unit 30 includes a plurality of heat exchanger unitsensors S2 (see FIG. 12) for detecting states (mainly, a pressure or atemperature) of the refrigerant in each of the refrigerant circuits RC.The heat exchanger unit sensors S2 (refrigerant state sensors) are apressure sensor or a temperature sensor such as a thermistor or athermocouple. The heat exchanger unit sensors S2 include sixthtemperature sensors 41 that detect temperatures of the refrigerant onliquid sides (in the refrigerant pipes Pb) of the heat exchangers 33(the refrigerant flow paths RP) and seventh temperature sensors 42 thatdetect temperatures of the refrigerant on gas sides (in the refrigerantpipes Pc) of the heat exchangers 33 (the refrigerant flow paths RP), forexample. The heat exchanger unit sensors S2 also include third pressuresensors 43 that detect pressures of the refrigerant on the liquid sides(in the refrigerant pipes Pb) of the heat exchangers 33 (the refrigerantflow paths RP) and fourth pressure sensors 44 that detect pressures ofthe refrigerant on the gas sides (in the refrigerant pipes Pc) of theheat exchangers 33 (the refrigerant flow paths RP), for example.

The heat exchanger unit 30 also includes an exhaust fan unit 45 fordischarging the leaking refrigerant from the heat exchanger unit 30 (therefrigerant circuits RC) when a refrigerant leak occurs in the heatexchanger unit 30. The exhaust fan unit 45 includes an exhaust fan 46.The exhaust fan 46 is driven in synchronization with a drive source(e.g., a fan motor). The exhaust fan 46, when it is driven, generates afirst air flow AF1 flowing from an inside to an outside (here, thefacility device room R described later) of the heat exchanger unit 30.The type of the exhaust fan 46 is not limited and examples of theexhaust fan 46 include a sirocco fan and a propeller fan. The exhaustfan unit 45 also includes a flow path forming member 47 forming a flowpath for the first air flow AF1 (see FIG. 11). The flow path formingmember 47 is not limited insofar as it is a member forming an air flowpath for the first air flow AF1, and is a duct, hose, or the like, forexample. A suction hole 47 a (see FIGS. 10, 11) for the first air flowAF1 is formed in the flow path forming member 47.

The heat exchanger unit 30 also includes a cooling fan 48. The coolingfan 48 is driven in synchronization with a drive source (e.g., a fanmotor). The cooling fan 48, when it is driven, generates a second airflow AF2 for cooling electric components (heat generating components)disposed in the heat exchanger unit 30. The cooling fan 48 is arrangedsuch that the second air flow AF2 exchanges heat with the heatgenerating components while flowing around the heat generatingcomponents and then flows from the inside of the heat exchanger unit 30to the outside (here, the facility device room R). The type of thecooling fan 48 is not limited and examples of the cooling fan 48 includea sirocco fan and a propeller fan.

The heat exchanger unit 30 also has the heat exchanger unit control unit49 that controls operations and states of the respective devicesincluded in the heat exchanger unit 30. The heat exchanger unit controlunit 49 includes, in order to perform its functions, a microcomputerhaving a microprocessor and a memory chip on which programs performed bythe microprocessor are stored, various kinds of electric components, andthe like. The heat exchanger unit control unit 49 is electricallyconnected to the respective devices (e.g., the devices 31, 32, 36, 46,and 48) and the heat exchanger unit sensors S2 included in the heatexchanger unit 30 to exchange signals with the devices and the heatexchanger unit sensors S2. The heat exchanger unit control unit 49 iselectrically connected to the heat-source-side unit control unit 29, acontrol unit (not illustrated) or a remote controller (not illustrated)disposed in each of the use-side units 60, or the like via communicationlines to exchange control signals with the heat-source-side unit controlunit 29, the control unit, the remote controller, or the like. Thesecond air flow AF2 generated by the cooling fan 48 cools the electriccomponents included in the heat exchanger unit control unit 49.

(2-3) Use-Side Unit 60

The use-side units 60 are facilities that utilize the heat medium cooledor heated by the heat exchanger unit 30. Each of the use-side units 60is connected to the heat exchanger unit 30 via the first heat mediumconnection pipe H1, the second heat medium connection pipe H2, and thelike. The use-side units 60 form the heat medium circuit HC togetherwith the heat exchanger unit 30.

In the embodiment, each of the use-side units 60 is an air handling unitor a fan coil unit that performs air conditioning by causing the heatmedium cooled or heated by the heat exchanger unit 30 and air toexchange heat with each other.

In FIG. 1, only one of the use-side units 60 is shown. However, the heatload processing system 100 may include the plurality of use-side unitsand the heat medium cooled or heated by the heat exchanger unit 30 maybe divided and sent to the plurality of use-side units. If the heat loadprocessing system 100 includes the plurality of use-side units, all theplurality of use-side units may be of the same kind or the plurality ofuse-side units may include a plurality of kinds of facilities.

(2-4) Liquid-Side Connection Pipe LP, Gas-Side Connection Pipe GP

Each of the liquid-side connection pipes LP and each of the gas-sideconnection pipes GP connect the heat exchanger unit 30 and thecorresponding heat-source-side unit 10 to form the flow path for therefrigerant. The liquid-side connection pipes LP and the gas-sideconnection pipes GP are constructed at an installation site. Actually,each of the liquid-side connection pipes LP or each of the gas-sideconnection pipes GP may include a single pipe or a plurality of pipesconnected to each other via joints or the like.

(2-5) First Heat Medium Connection Pipe H1, Second Heat MediumConnection Pipe H2

The first heat medium connection pipe H1 and the second heat mediumconnection pipe H2 connect the heat exchanger unit 30 and thecorresponding use-side unit 60 to form the flow path for the heatmedium. The first heat medium connection pipe H1 and the second heatmedium connection pipe H2 are constructed at the installation site.Actually, the first heat medium connection pipe H1 or the second heatmedium connection pipe H2 may include a single pipe or a plurality ofpipes connected to each other via joints or the like.

(2-6) Refrigerant Leak Sensor 70

The refrigerant leak sensor 70 is a sensor for detecting the refrigerantleak in the space (here, the facility device room R described later)where the heat exchanger unit 30 is disposed. Specifically, therefrigerant leak sensor 70 detects the leaking refrigerant in the heatexchanger unit 30. In the embodiment, a known general-purpose product isused as the refrigerant leak sensor 70 in accordance with the type ofthe refrigerant filled in the refrigerant circuits RC. The refrigerantleak sensor 70 is disposed in the space where the heat exchanger unit 30is disposed. In the embodiment, the refrigerant leak sensor 70 isdisposed in the heat exchanger unit 30.

The refrigerant leak sensor 70 continuously or intermittently outputselectric signals (refrigerant leak sensor detection signals)corresponding to detection values to the controller 80. Morespecifically, the refrigerant leak sensor detection signal output fromthe refrigerant leak sensor 70 changes in voltage in accordance with aconcentration of the refrigerant detected by the refrigerant leak sensor70. In other words, the refrigerant leak sensor detection signal isoutput to the controller 80 in such a manner that the concentration ofthe leaking refrigerant in the space where the refrigerant leak sensor70 is disposed (more specifically, the concentration of the refrigerantdetected by the refrigerant leak sensor 70) in addition to presence orabsence of the refrigerant leak in the refrigerant circuits RC can beidentified. In other words, the refrigerant leak sensor 70 correspondsto “a refrigerant leak detection unit” that detects the leakingrefrigerant in the heat exchanger unit 30 (the facility device room R)by directly detecting the refrigerant (more specifically, theconcentration of the refrigerant) flowing out of the refrigerant circuitRC.

(2-7) Controller 80

The controller 80 is a computer that controls the operation of the heatload processing system 100 by controlling the states of the respectivedevices. In the embodiment, the heat-source-side unit control unit 29,the heat exchanger unit control unit 49, and devices (e.g., the controlunit or the remote controller disposed in each of the use-side units)connected to the control units configure the controller 80 by beingconnected to each other via communication lines. In other words, in theembodiment, the controller 80 is implemented by the heat-source-sideunit control unit 29, the heat exchanger unit control unit 49, and thedevices connected to the control units cooperating with each other. Thecontroller 80 will be described in detail later.

(3) Flows of Refrigerant and Heat Medium During Operation

Next, a description will be given of flows of the refrigerant in each ofthe refrigerant circuits RC and the heat medium in the heat mediumcircuit HC. The heat load processing system 100 mainly performs theforward cycle operation and the reverse cycle operation. In the forwardcycle operation, the refrigerant circulating through each of therefrigerant circuits RC cools the heat medium circulating through theheat medium circuit HC and the cooled heat medium cools an object to becooled (heat load). In the reverse cycle operation, the refrigerantcirculating through each of the refrigerant circuits RC heats the heatmedium circulating through the heat medium circuit HC and the heatedheat medium heats the object to be heated (heat load). In each of theoperations, the heat-source-side unit(s) 10 to operate is(are)appropriately selected in accordance with the heat load(s). In each ofthe operations, the numbers of rotations of the compressor 11 and theheat-source-side fan 20 of the operating heat-source-side unit 10 andthe pump 36 of the heat exchanger unit 30 are appropriately adjusted.

(3-1) Flow During Forward Cycle Operation

During the forward cycle operation, the four-way switching valve 13 iscontrolled in the forward cycle state. When the forward cycle operationstarts, in the operating heat-source-side unit 10 (the refrigerantcircuit RC), the compressor 11 draws in, compresses, and then dischargesthe refrigerant. The gas refrigerant discharged from the compressor 11flows into the heat-source-side heat exchanger 14.

The gas refrigerant having flowed into the heat-source-side heatexchanger 14 condenses (or radiates heat) as a result of heat exchangewith the heat-source-side air flow supplied by the heat-source-side fan20 in the heat-source-side heat exchanger 14. The refrigerant havingflowed out of the heat-source-side heat exchanger 14 is divided whileflowing through the sixth pipe P6.

A branch of the refrigerant divided during flowing through the sixthpipe P6 flows into the heat-source-side first control valve 16 where therefrigerant is decompressed or the flow rate of the refrigerant isadjusted in accordance with the opening degree of the heat-source-sidefirst control valve 16, and then flows into the main flow path 151 ofthe subcooler 15. The refrigerant having flowed into the main flow path151 of the subcooler 15 is further cooled and turns into the liquidrefrigerant in the subcooled state as a result of heat exchange with therefrigerant flowing through the sub flow path 152. The liquidrefrigerant having flowed out of the main flow path 151 of the subcooler15 flows out of the heat-source-side unit 10 and flows into the heatexchanger unit 30 via the liquid-side connection pipe LP.

The other branch of the refrigerant divided during flowing through thesixth pipe P6 flows into the heat-source-side second control valve 17where the refrigerant is decompressed or the flow rate of therefrigerant is adjusted in accordance with the opening degree of theheat-source-side second control valve 17, and then flows into the subflow path 152 of the subcooler 15. The refrigerant having flowed intothe sub flow path 152 of the subcooler 15 exchanges heat with therefrigerant flowing through the main flow path 151 and is then injectedinto the compressor 11 via the eleventh pipe P11.

The refrigerant having flowed into the heat exchanger unit 30 flows intothe expansion valve 31 via the corresponding refrigerant pipe Pa wherethe refrigerant is decompressed to a low pressure in the refrigerationcycle in accordance with the opening degree of the expansion valve 31,and then flows into the corresponding refrigerant flow path RP of theheat exchanger 33. The refrigerant having flowed into the refrigerantflow path RP of the heat exchanger 33 evaporates as a result of heatexchange with the heat medium flowing through the heat medium flow pathHP and flows out of the heat exchanger 33. The refrigerant having flowedout of the heat exchanger 33 flows out of the heat exchanger unit 30 viathe refrigerant pipes Pc and Pd and the like.

The refrigerant having flowed out of the heat exchanger unit 30 flowsinto the heat-source-side unit 10 via the gas-side connection pipe GP.The refrigerant having flowed into the heat-source-side unit 10 flowsinto the accumulator 12 via the first pipe P1, the second pipe P2, andthe like. The refrigerant having flowed into the accumulator 12 istemporarily stored in the accumulator 12, and then is drawn into thecompressor 11 again.

In the heat medium circuit HC, the pump 36 sends the heat medium fromthe first heat medium connection pipe H1 into the heat medium flow pathsHP of the heat exchangers 33. The heat medium sent to the heat mediumflow paths HP is cooled as a result of heat exchange with therefrigerant flowing through the refrigerant flow paths RP and flows outof the heat exchangers 33. The heat medium having flowed out of the heatexchangers 33 flows out of the heat exchanger unit 30 via the heatmedium pipe Hd and the like.

The heat medium having flowed out of the heat exchanger unit 30 is sentto the operating use-side unit(s) 60 via the second heat mediumconnection pipe H2 and the like. The heat medium sent to each of theuse-side units 60 is heated as a result of heat exchange with apredetermined object to be cooled (here, air in a living space SPdescribed later) and flows out of the use-side unit 60. The heat mediumhaving flowed out of the use-side unit 60 flows into the heat exchangerunit 30 again via the first heat medium connection pipe H1 and the like.

(3-2) Flows During Reverse Cycle Operation

During the reverse cycle operation, the four-way switching valve 13 iscontrolled in the reverse cycle state. When the reverse cycle operationstarts, in the operating heat-source-side unit 10 (the refrigerantcircuit RC), the compressor 11 draws in, compresses, and then dischargesthe refrigerant. The gas refrigerant discharged from the compressor 11flows out of the heat-source-side unit 10 via the fourth pipe P4, thefirst pipe P1, and the like.

The refrigerant having flowed out of the heat-source-side unit 10 flowsinto the heat exchanger unit 30 via the gas-side connection pipe GP. Therefrigerant having flowed into the heat exchanger unit 30 flows into thecorresponding refrigerant flow path RP of the heat exchanger 33 via thecorresponding refrigerant pipes Pd, Pc, and the like. The refrigeranthaving flowed into the refrigerant flow path RP of the heat exchanger 33condenses (or radiates heat) as a result of heat exchange with the heatmedium flowing through the heat medium flow path HP and flows out of theheat exchanger 33.

The refrigerant having flowed out of the heat exchanger 33 flows, viathe refrigerant pipe Pb and the like, into the expansion valve 31 wherethe refrigerant is decompressed to the low pressure in the refrigerationcycle in accordance with the opening degree of the expansion valve 31,and then flows out of the heat exchanger unit 30 via the refrigerantpipe Pa and the like.

The refrigerant having flowed out of the heat exchanger unit 30 flowsinto the heat-source-side unit 10 via the liquid-side connection pipe LPand the like. The refrigerant having flowed into the heat-source-sideunit 10 flows through the seventh pipe P7, the sixth pipe P6, and thelike and flows into the heat-source-side heat exchanger 14. Therefrigerant having flowed into the heat-source-side heat exchanger 14evaporates in the heat-source-side heat exchanger 14 as a result of heatexchange with the heat-source-side air flow sent by the heat-source-sidefan 20 and flows out of the heat-source-side heat exchanger 14.

The refrigerant having flowed out of the heat-source-side heat exchanger14 flows into the accumulator 12 via the fifth pipe P5, the second pipeP2, and the like. The refrigerant having flowed into the accumulator 12is temporarily stored in the accumulator 12, and then is drawn into thecompressor 11 again.

In the heat medium circuit HC, the pump 36 sends the heat medium fromthe first heat medium connection pipe H1 into the heat medium flow pathsHP of the heat exchangers 33. The heat medium sent into the heat mediumflow paths HP is heated as a result of heat exchange with therefrigerant flowing through the refrigerant flow paths RP and flows outof the heat exchangers 33. The heat medium having flowed out of the heatexchangers 33 flows out of the heat exchanger unit 30 via the heatmedium pipe Hd and the like.

The heat medium having flowed out of the heat exchanger unit 30 is sentto the operating use-side unit(s) 60 via the second heat mediumconnection pipe H2 and the like. The heat medium sent to the use-sideunit 60 is cooled as a result of heat exchange with the object to beheated (here, the air in the living space SP described later) and flowsout of the use-side unit 60. The heat medium having flowed out of theuse-side unit 60 flows into the heat exchanger unit 30 again via thefirst heat medium connection pipe H1 and the like.

(4) Manner of Installation of Heat Load Processing System 100

FIG. 3 is a diagrammatic illustration showing a manner of installationof the heat load processing system 100. An installation place of theheat load processing system 100 is not limited and may be a building, acommercial facility, a factory, or the like, for example. In theembodiment, the heat load processing system 100 is installed in themanner shown in FIG. 3 in a building B1. The building B1 has a pluralityof floors. The number of floors, the number of rooms, and the like ofthe building B1 can be changed as appropriate.

The facility device room R is provided in the building B1. The facilitydevice room R is a space where electric facilities such as a switchboardand a power generator or a cold energy device such as a boiler aredisposed. The facility device room R is a space into and out of whichpeople can come and in which people can stay. For example, the facilitydevice room R is a space such as a basement room where people can walk.In the embodiment, the facility device room R is positioned on alowermost floor of the building B1. The building B1 is also providedwith the living spaces SP where people do activities. The building B1 isprovided with the plurality of living spaces SP. In the embodiment, theliving spaces SP are positioned on a floor above the floor provided withthe facility device room R.

In FIG. 3, the heat-source-side units 10 are installed on a rooftop ofthe building B1. The heat exchanger unit 30 is installed in the facilitydevice room R. In relation to this, the liquid-side connection pipes LPand the gas-side connection pipes GP extend along a vertical directionbetween the rooftop and the facility device room R. To put it moreconcretely, in the facility device room R, as shown in FIG. 4, the heatexchanger unit 30 is installed together with the other devices (devicesOD1 to OD3). The devices OD1 to OD3 are not limited and may be theboiler, the power generator, the switchboard, and the like, for example.It is also possible that only the heat exchanger unit 30 is installed inthe facility device room R.

In FIG. 3, the respective use-side units 60 are disposed in thecorresponding living spaces SP. In relation to this, the first heatmedium connection pipe H1 and the second heat medium connection pipe H2extend along the vertical direction between the living spaces SP and thefacility device room R.

In the building B1, ventilators 200 that provide ventilation (forcedventilation or natural ventilation) of the facility device room R areprovided. The respective ventilators 200 are installed in the facilitydevice room R. Specifically, in the facility device room R, aventilation fan 210 is installed as the ventilator 200. The ventilationfan 210 is connected to a plurality of ventilation ducts D. Theventilation fan 210, when it is driven, exhausts air (room air RA) inthe facility device room R to an outside space as exhaust air EA andsupplies air (outside air OA) in the outside space into the facilitydevice room R as supplied air SA to thereby provide the ventilation ofthe facility device room R. In other words, the ventilation fan 210corresponds to “the ventilator” that provides the ventilation in thefacility device room R. The ventilation fan 210 is electricallyconnected to the controller 80 via an adaptor 80 a (see FIG. 12). Thecontroller 80 can control operations (start and stop and the number ofrotations) of the ventilation fan 210. The control of the ventilationfan 210 appropriately switches between an intermittent operating mode inwhich the ventilation fan 210 operates intermittently and a continuousoperating mode in which the ventilation fan 210 operates continuously.

In the facility device room R, an opening/closing mechanism 220 isinstalled as the ventilator 200. The opening/closing mechanism 220 is amechanism switchable between an open state for communicating between thefacility device room R and another space (e.g., the outside space) and aclosed state for interrupting between the facility device room R and theother space from each other. In other words, the opening/closingmechanism 220 opens and closes an opening that communicates between thefacility device room R and the other space. For example, theopening/closing mechanism 220 is a door, a hatch, a window, a shutter,or the like opening and closing of which is controllable. Theopening/closing mechanism 220 is electrically connected to thecontroller 80 via an adaptor 80 b (see FIG. 12). The controller 80controls the state (the open state or the closed state) of theventilation fan 210.

(5) Manner of Configuration of Heat Exchanger Unit 30

FIG. 5 is a perspective view of the heat exchanger unit 30. The heatexchanger unit 30 has a casing 50 that houses the respective devices.FIG. 6 is a diagrammatic illustration showing a manner of disposition ofthe devices in the casing 50 in a plan view. FIG. 7 is a diagrammaticillustration showing the manner of disposition of the devices in thecasing 50 in a side view. FIG. 8 is a diagrammatic illustration showingthe manner of disposition of the devices in the casing 50 in a frontview.

In the embodiment, the casing 50 houses the same number of (here, four)units (hereinafter referred to as “device units R1”) each forming theone refrigerant circuit RC (refrigerant system) as the number ofrefrigerant circuits RC. In other words, the casing 50 collectivelyhouses the plurality of device units R1 (refrigerant system componentdevices) forming the different refrigerant systems. In the embodiment,as shown in FIGS. 6 to 8, the casing 50 houses the device unit R1including the refrigerant flow path RP of the first heat exchanger 34 orthe second heat exchanger 35, the expansion valve 31, the on-off valve32, and the refrigerant pipes Pa to Pd together with the other deviceunits R1. The casing 50 also houses the devices forming the heat mediumcircuit HC.

The casing 50 has a substantially rectangular parallelepiped shape. Thecasing 50 is installed by use of installation legs, a mount, or thelike. The casing 50 includes a lower space Sa and an upper space Sbformed inside itself. The lower space Sa and the upper space Sb are notcompletely separate from each other and partially communicate with eachother.

In the lower space Sa, the respective expansion valves 31, therespective on-off valves 32, the heat exchangers 33, the pump 36, therespective refrigerant pipes Pa to Pd, the heat medium pipes Ha to Hd,and the heat exchanger unit sensors S2 are disposed. In the embodiment,as shown in FIG. 6, in the lower space Sa, the first heat exchanger 34,the second heat exchanger 35, and the pump 36 are disposed in this orderfrom the right to the left. In front of the heat exchangers 33, therespective expansion valves 31, the respective on-off valves 32, and therespective refrigerant pipes Pa to Pd are arranged systematically tocorrespond to positions of the refrigerant flow paths RP with which thevalves 31 and 32 and the pipes Pa to Pd communicate, respectively.Behind the pump 36, the heat medium pipe Ha is disposed. The heat mediumpipe Hb extends from a front side of the pump 36 toward a rear side ofthe second heat exchanger 35. The heat medium pipes Hc and Hd aredisposed behind the heat exchangers 33.

In FIGS. 7 and 8, a portion shown by a reference sign “A1” is a highestportion (hereinafter referred to as “uppermost portion A1”) of therespective refrigerant pipes Pa to Pd disposed in the heat exchangerunit 30. The uppermost portion A1 is positioned at a heightcorresponding to a vertical length h1 from a bottom portion of thecasing 50.

In FIGS. 7 and 8, a portion shown by a reference sign “A2” is a lowestportion (hereinafter referred to as “lowermost portion A2”) of therespective refrigerant pipes Pa to Pd in the heat exchanger unit 30. Thelowermost portion A2 is positioned at a height corresponding to avertical length h2 from the bottom portion of the casing 50. Thelowermost portion A2 is positioned at a height corresponding to avertical length h2 from the bottom portion of the casing 50.

The upper space Sb is a space positioned above the lower space Sa. Inthe upper space Sb, an electric component box 55 for housing therein theheat exchanger unit control unit 49 is disposed.

The casing 50 has a bottom plate 58 shown in FIGS. 9 and 10. FIG. 9 is adiagrammatic illustration of the bottom plate 58 in a plan view. FIG. 10is a diagrammatic illustration of the bottom plate 58 in a side view.

The bottom plate 58 is a member forming the bottom portion of the casing50. The bottom plate 58 is one of members forming the lower space Sa.The bottom plate 58 is disposed below the heat exchangers 33. The bottomplate 58 also functions as a drain pan that receives condensed waterdropping from the heat exchangers 33. The bottom plate 58 has asubstantially rectangular bottom face portion 581 in the plan view. Thebottom plate 58 has a discharge port 58 a formed to discharge the waterreceived by the bottom face portion 581. The discharge port 58 a isdisposed near a center of one side of the bottom face portion 581 in theplan view (see FIG. 9). The bottom face portion 581 is inclined in sucha manner as to form a descending slope toward the discharge port 58 a.In relation to this, the bottom plate 58 has a depth increasing towardthe discharge port 58 a. In other words, in the bottom plate 58, a space(bottom plate immediate upper space S1) deepening toward the dischargeport 58 a is formed above the bottom face portion 581.

The refrigerant leak sensor 70 is disposed above the bottom face portion581 of the bottom plate 58. In other words, the refrigerant leak sensor70 is disposed in the bottom plate immediate upper space Si. To put itmore specifically, the refrigerant leak sensor 70 is disposed near thedischarge port 58 a. In other words, the refrigerant leak sensor 70 isdisposed at a position where the bottom plate immediate upper space S1becomes deep.

FIG. 11 is a diagrammatic illustration schematically showing a manner ofdisposition of the exhaust fan unit 45 and the cooling fan 48 in thecasing 50. The casing 50 has a discharge hole 50 a formed to dischargethe first air flow AF1 generated by the exhaust fan 46. The dischargehole 50 a discharges the first air flow AF1 outside from the heatexchanger unit 30. The discharge hole 50 a is positioned neat an upperend of the lower space Sa. To put it more concretely, the discharge hole50 a is disposed at a higher position than the height h1. In otherwords, the discharge hole 50 a is formed at the higher position than theuppermost portion A1 (the highest portion of the refrigerant pipeshoused in the heat exchanger unit 30). The discharge hole 50 acommunicates with a secondary side (blow-out side) of the exhaust fan46.

The casing 50 houses the exhaust fan unit 45 disposed in the lower spaceSa. The exhaust fan unit 45 is disposed in such a manner as to take inthe first air flow AF1 from the bottom plate immediate upper space S1and discharge it from the discharge hole 50 a in the lower space Sa. Toput it more concretely, the flow path forming member 47 of the exhaustfan unit 45 is disposed to extend from the bottom plate immediate upperspace S1 along the vertical direction.

One end of the flow path forming member 47 is an opening and functionsas the suction hole (hereinafter referred to as “suction hole 47 a”) fordrawing in the first air flow AF1. The suction hole 47 a is disposed ata lower position than the height h1 (see FIG. 11). In other words, thesuction hole 47 a for the first air flow AF1 is formed at the lowerposition than the uppermost portion A1 (the highest portion of therefrigerant pipes housed in the heat exchanger unit 30). The suctionhole 47 a is formed at the lower position than the lowermost portion A2(the lowest portion of the refrigerant pipes housed in the heatexchanger unit 30). To put it more specifically, the suction hole 47 ais disposed in the bottom plate immediate upper space S1 (see FIG. 10).In other words, the suction hole 47 a is formed in the space in thebottom plate 58 (drain pan). From a different perspective, the suctionhole 47 a can be regarded as being disposed in the bottom plate 58.

The other end of the flow path forming member 47 is an opening andcommunicates with a primary side (suction side) of the exhaust fan 46.The other end of the flow path forming member 47 is at a higher positionthan the height h1. In other words, the other end of the flow pathforming member 47 is formed at the higher position than the uppermostportion A1 (the highest portion of the refrigerant pipes housed in theheat exchanger unit 30).

The exhaust fan 46 is disposed near the discharge hole 50 a. The exhaustfan 46 is at a higher position than the height h1. In other words, theexhaust fan 46 is formed at the higher position than the uppermostportion A1 (the highest portion of the refrigerant pipes housed in theheat exchanger unit 30). The exhaust fan 46 is disposed near the heatmedium pipes Ha to Hd in the lower space Sa. This reduces flowing of theleaking refrigerant into the living spaces SP via the heat medium pipesHa to Hd when the refrigerant leak occurs in the heat exchanger unit 30.

The casing 50 houses the cooling fan 48 disposed in the upper space Sb.The cooling fan 48 is disposed in the upper space Sb such that thesecond air flow AF2 flows around the heat generating components includedin the heat exchanger unit control unit 49 and then flows to the outside(here, the facility device room R). The cooling fan 48 is disposed nearthe heat exchanger unit control unit 49 housed in the electric componentbox 55. In the embodiment, the cooling fan 48 is disposed at a higherposition than the height h1. In other words, the cooling fan 48 isdisposed at the higher position than the exhaust fan 46.

(6) Details of Controller 80

In the heat load processing system 100, the heat-source-side unitcontrol unit 29 and the heat exchanger unit control unit 49 areconnected via the communication line to thereby configure the controller80. FIG. 12 is a block diagram schematically showing the controller 80and the components connected to the controller 80.

The controller 80 has a plurality of control modes and controlsoperations of the respective devices in accordance with a control modein which the controller 80 is to be placed. In the embodiment, thecontroller 80 includes, as the control modes, the normal operating modein which the controller 80 is placed during operation (when norefrigerant leak is occurring) and the refrigerant leak mode in whichthe controller 80 is placed when a refrigerant leak occurs (morespecifically, when the refrigerant leak is detected).

The controller 80 is electrically connected to the devices included inthe heat load processing system 100, e.g., the compressor 11, thefour-way switching valve 13, the heat-source-side first control valve16, the heat-source-side second control valve 17, the heat-source-sidefan 20, and the heat-source-side sensors S1 included in each of theheat-source-side units 10, the devices included in the heat exchangerunit 30 (concretely, the respective expansion valves 31, the respectiveon-off valves 32, the pump 36, the exhaust fan 46, the cooling fan 48,and the heat exchanger unit sensors S2), and the refrigerant leak sensor70. The controller 80 is also electrically connected to the ventilators200 disposed in the facility device room R. To put it more concretely,the controller 80 is electrically connected to the ventilation fan 210via the adaptor 80 a and connected to the opening/closing mechanism 220via the adaptor 80 b. The controller 80 is also electrically connectedto an output device 300 capable of outputting predetermined information(e.g., a display capable of outputting displayed information and aspeaker capable of outputting sound information).

The controller 80 mainly includes a storage unit 81, an input controlunit 82, a mode control unit 83, a refrigerant leak determination unit84, a device control unit 85, a drive signal output unit 86, and aninformation output control unit 87. These functional units in thecontroller 80 are implemented by the CPUs, the memories, and the variouselectric and electronic components included in the heat-source-side unitcontrol unit 29 and/or the heat exchanger unit control unit 49cooperating with each other.

(6-1) Storage Unit 81

The storage unit 81 includes, for example, a read only memory (ROM), arandom access memory (RAM), and a flash memory. The storage unit 81 hasa volatile storage region and a nonvolatile storage region. The storageunit 81 has a program storage region M1 in which a control program thatdefines processing to be performed by each unit of the controller 80 isstored.

The storage unit 81 has a detection value storage region M2 in whichdetection values of the respective sensors are stored. The detectionvalue storage region M2 stores the detection values (the suctionpressure, the discharge pressure, the suction temperature, the dischargetemperature, the temperatures and the pressures of the refrigerantflowing into the heat exchangers 33 or the temperatures and thepressures of the refrigerant flowing out of the heat exchangers 33, andthe like) of the respective heat-source-side sensors S1 and therespective heat exchanger unit sensors S2, for example.

The storage unit 81 has a sensor signal storage region M3 in which therefrigerant leak sensor detection signal sent from the refrigerant leaksensor 70 (the detection value of the refrigerant leak sensor 70) isstored. The refrigerant leak signal stored in the sensor signal storageregion M3 is updated every time the refrigerant leak signal output fromthe refrigerant leak sensor 70 is received.

The storage unit 81 has a command storage region M4 in which a commandinput by a user via an input device (not illustrated) is stored.

In addition, the storage unit 81 is provided with a plurality of flagshaving the predetermined numbers of bits. For example, the storage unit81 is provided with a control mode determination flag M5 based on whichthe control mode in which the controller 80 is placed can be determined.The control mode determination flag M5 includes the bits correspondingin number to the control modes and the bits corresponding to the controlmode in which the controller 80 is placed are set.

The storage unit 81 is provided with a refrigerant leak detection flagM6 based on which it is possible to determine the refrigerant leak hasbeen detected in the heat exchanger unit 30. More specifically, therefrigerant leak detection flag M6 includes the bits corresponding innumber to the refrigerant circuits RC (device units R1) and the bitscorresponding to the refrigerant circuit RC (refrigerant leakingcircuit) in which the refrigerant leak is assumed to have occurred areset. In other words, the refrigerant leak detection flag M6 isconfigured to make it possible to determine in which refrigerant circuitRC the refrigerant leak has occurred when the refrigerant leak hasoccurred in any of the refrigerant circuits RC. The refrigerant leakdetermination unit 84 switches the refrigerant leak detection flag M6.

(6-2) Input Control Unit 82

The input control unit 82 is a functional unit that plays a role as aninterface for receiving signals output from the respective devicesconnected to the controller 80. For example, the input control unit 82receives the signals output from the respective sensors (S1, S2), theremote controller, and the like, and then stores the signals in thecorresponding storage regions in the storage unit 81 or sets thepredetermined flag.

(6-3) Mode Control Unit 83

The mode control unit 83 is a functional unit that switches the controlmode. The mode control unit 83 switches the control mode to the normaloperating mode under normal conditions (when the refrigerant leakdetection flag M6 is not set). The mode control unit 83 switches thecontrol mode to the refrigerant leak mode when the refrigerant leakdetection flag M6 is set. The mode control unit 83 sets the control modedetermination flag M5 in accordance with the control mode in which thecontroller 80 is placed.

(6-4) Refrigerant Leak Determination Unit 84

The refrigerant leak determination unit 84 is a functional unit thatdetermines whether the refrigerant leak is occurring in the refrigerantcircuit RC and identifies the refrigerant leaking circuit (refrigerantleaking system). To put it concretely, the refrigerant leakdetermination unit 84 determines that the refrigerant leak is occurringin the refrigerant circuit RC and sets the refrigerant leak detectionflag M6 when a predetermined refrigerant leak detection condition issatisfied.

In the embodiment, whether or not the refrigerant leak detectioncondition is satisfied is determined based on the refrigerant leaksensor detection signal in the sensor signal storage region M3. To putit concretely, the refrigerant leak detection condition is satisfiedwhen a voltage according to any of the refrigerant leak sensor detectionsignals (a detection value of the refrigerant leak sensor 70) continuesto be higher than or equal to a predetermined first reference value fora predetermined time t1 or longer. The first reference value is a value(the concentration of the refrigerant) with which the refrigerant leakis assumed in the refrigerant circuit RC. The predetermined time t1 isset to such a time that the refrigerant leak sensor detection signal canbe determined not to be momentary. The predetermined time t1 isappropriately set in accordance with the type of refrigerant filled inthe refrigerant circuits RC, specifications of the respective devices,the installation environment, or the like and defined in the controlprogram. The refrigerant leak determination unit 84 is configured to beable to measure the predetermined time t1. The first reference value isappropriately set in accordance with the type of refrigerant filled inthe refrigerant circuits RC, design specifications, the installationenvironment, and the like and defined in the control program.

The refrigerant leak determination unit 84 performs refrigerant leakingcircuit identification processing if the refrigerant leak detectioncondition is satisfied. The refrigerant leaking circuit identificationprocessing is processing for identifying the refrigerant leaking circuit(i.e., processing for determining in which refrigerant circuit RC therefrigerant leak has occurred).

The refrigerant leak determination unit 84 identifies the refrigerantleaking circuit (refrigerant circuit RC in which the refrigerant leak isoccurring) based on any or all of the detection values of the respectiveheat-source-side sensors S1 and the respective heat exchanger unitsensors S2 in the refrigerant leaking circuit identification processing.To put it concretely, the refrigerant leak determination unit 84requests the device control unit 85 to control the respectiverefrigerant circuits RC (device units R1) in operating states. Then,after a predetermined time (a time required for the refrigerant circuitsRC not suffering from the refrigerant leak to come into stable statesafter startup) lapses, the refrigerant leak determination unit 84compares the values of the heat-source-side sensors S1 and the heatexchanger unit sensors S2 of the respective refrigerant circuits RC witheach other to identify the refrigerant leaking circuit. In other words,the refrigerant leak determination unit 84 identifies, while causingeach of the refrigerant circuits RC (device units R1) to operate, therefrigerant leaking circuit based on how high any or all of thedetection value (suction pressure) of the first pressure sensor 27, thedetection value (discharge pressure) of the second pressure sensor 28,the detection value of the third pressure sensor 43, and the detectionvalue of the fourth pressure sensor 44 of each of the refrigerantcircuits RC is (are). For example, the refrigerant leak determinationunit 84 identifies the refrigerant leaking circuit based on a degree ofa pressure drop of the high-pressure refrigerant in the refrigerantleaking circuit identification processing. In place of or in addition tothis, the refrigerant leak determination unit 84 identifies therefrigerant leaking circuit based on how high any or all of thedetection value (suction temperature) of the first temperature sensor21, the detection value (discharge temperature) of the secondtemperature sensor, the detection value (condensation temperature orevaporation temperature) of the third temperature sensor 23, thedetection value of the fourth temperature sensor 24, the detection valueof the fifth temperature sensor 25, the detection value of the sixthtemperature sensor 41, and the detection value of the seventhtemperature sensor 42 of each of the refrigerant circuits RC is (are).

In other words, the refrigerant leak determination unit 84 and therefrigerant leak sensor 70 correspond to a “refrigerant leak detectionunit” that detects the refrigerant leak in the heat exchanger unit 30(facility device room R) and identifies the refrigerant leaking circuit(i.e., identifies in which refrigerant circuit RC the refrigerant leakhas occurred).

The refrigerant leak determination unit 84 sets the bits correspondingto the refrigerant leaking circuit in the refrigerant leak detectionflag M6 after the identification of the refrigerant leaking circuit.Thus, if the refrigerant leak occurs in the heat exchanger unit 30, theother functional units can grasp the fact that the refrigerant leak hasoccurred and the refrigerant circuit RC in which the refrigerant leakhas occurred.

(6-5) Device Control Unit 85

The device control unit 85 controls, based on the control program, theoperations of the respective devices (e.g., the devices 11, 13, 16, 17,20, 31, 32, 36, 46, 48) included in the heat load processing system 100,in accordance with a situation. The device control unit 85 also controlsthe states of the ventilators 200 (the ventilation fan 210 and theopening/closing mechanism 220) installed in the facility device room R.The device control unit 85 refers to the control mode determination flagM5, thereby determining a control mode in which the controller 80 isplaced, and controls the operations of the respective devices, based onthe determined control mode. The device control unit 85 controls theoperations of the respective devices at the requests of the otherfunctional units.

In the normal operating mode, for example, the device control unit 85controls an operating capacity of the compressor 11, theheat-source-side fan 20, opening degrees of the heat-source-side firstcontrol valve 16 and the heat-source-side second control valve 17, theopening degree of the expansion valve 31, the number of rotations of thepump 36, and the like in real time, such that the forward cycleoperation or the reverse cycle operation is performed in accordancewith, for example, set temperatures and the detection values of therespective sensors.

The device control unit 85 controls the four-way switching valve 13 inthe forward cycle state, causes the heat-source-side heat exchanger 14to function as the condenser (or the radiator) of the refrigerant, andcauses the heat exchangers 33 of the heat exchanger unit 30 to functionas the evaporators of the refrigerant during the forward cycleoperation. On the other hand, the device control unit 85 controls thefour-way switching valve 13 in the reverse cycle state, causes theheat-source-side heat exchanger 14 to function as the evaporator of therefrigerant, and causes the heat exchangers 33 of the heat exchangerunit 30 to function as the condensers (or the radiators) of therefrigerant during the reverse cycle operation.

Moreover, the device control unit 85 performs the following variouskinds of controls in accordance with situations. The device control unit85 is configured to be able to measure times.

(Refrigerant Leak First Control)

The device control unit 85 performs the refrigerant leak first controlwhen it is assumed that the refrigerant leak has occurred in the heatexchanger unit 30 (the refrigerant circuits RC). The refrigerant leakfirst control is a control for causing the fans (the exhaust fan 46 andthe cooling fan 48) disposed in the heat exchanger unit 30 to operatewith the predetermined numbers of rotations in order to prevent theconcentration of the leaking refrigerant from becoming locally high inthe heat exchanger unit 30. The device control unit 85 causes theexhaust fan 46 of the heat exchanger unit 30 to operate with thepredetermined number of rotations (air flow volume) in the refrigerantleak first control. The device control unit 85 also causes the coolingfan 48 of the heat exchanger unit 30 to operate with the predeterminednumber of rotations (air flow volume) in the refrigerant leak firstcontrol. In the embodiment, the numbers of rotations of the exhaust fan46 and the cooling fan 48 in the refrigerant leak first control are setto the maximum numbers of rotations (maximum air flow volumes). In otherwords, in the refrigerant leak first control, the device control unit 85causes the exhaust fan 46 or the cooling fan 48 to shift into theoperating state if the exhaust fan 46 or the cooling fan 48 is in a stopstate and causes the exhaust fan 46 or the cooling fan 48 to operatewith the maximum number of rotations if the exhaust fan 46 or thecooling fan 48 is already in the operating state.

As a result of this refrigerant leak first control, even if therefrigerant leak has occurred in the heat exchanger unit 30, the firstair flow AF1 generated by the exhaust fan 46 and the second air flow AF2generated by the cooling fan 48 stir the leaking refrigerant in the heatexchanger unit 30 or discharge the leaking refrigerant from the heatexchanger unit 30. Consequently, it is possible to reduce the hike ofthe concentration of the leaking refrigerant in the heat exchanger unit30.

(Refrigerant Leak Second Control)

The device control unit 85 performs the refrigerant leak second controlwhen it is assumed that the refrigerant leak has occurred in the heatexchanger unit 30 (the refrigerant circuits RC). The refrigerant leaksecond control is a control for increasing a ventilation air volume bythe ventilators 200 in order to prevent the concentration of the leakingrefrigerant from becoming locally high in the facility device room R.

The device control unit 85 increases the number of rotations (air flowvolume) of the ventilation fan 210 in the refrigerant leak secondcontrol. In the embodiment, the number of rotations of the ventilationfan 210 in the refrigerant leak second control is set to the maximumnumber of rotations (maximum air flow volume). In other words, in therefrigerant leak second control, the device control unit 85 causes theventilation fan 210 to shift into the operating state if the ventilationfan 210 is in a stop state and causes the ventilation fan 210 to operatewith the maximum number of rotations if the ventilation fan 210 isalready in the operating state. If the ventilation fan 210 is performingthe intermittent operation in the intermittent operation mode, thedevice control unit 85 performs the refrigerant leak second control toswitch the ventilation fan 210 into the continuous operating mode tocause the ventilation fan 210 to perform the continuous operation. Thus,an operating time per unit time of the ventilation fan 210 increases. Asa result, the ventilation air volume by the ventilation fan 210increases to facilitate discharge of the leaking refrigerant to theoutside space.

Moreover, the device control unit 85 switches the opening/closingmechanism 220 into the open state in the refrigerant leak secondcontrol. Thus, the facility device room R communicates with the otherspace. As a result, part of the leaking refrigerant in the facilitydevice room R flows out into the other space, which further reduces theconcentration of the leaking refrigerant from becoming locally high inthe facility device room R.

(Refrigerant Leak Third Control)

The device control unit 85 performs the refrigerant leak third controlif it is assumed that the refrigerant leak has occurred in the heatexchanger unit 30 (the refrigerant circuits RC) (concretely, if therefrigerant leak detection flag M6 is set). The device control unit 85controls the expansion valve 31 and the on-off valve 32 of therefrigerant leaking circuit (refrigerant circuit RC in which therefrigerant leak has occurred) into the closed states in the refrigerantleak third control. This reduces the inflow of the refrigerant from theheat-source-side unit 10 into the refrigerant leaking circuit andreduces a further refrigerant leak in the heat exchanger unit 30. Inother words, the refrigerant leak third control is a control forreducing outflow of the leaking refrigerant in the heat exchanger unit30 when the refrigerant leak has occurred.

Moreover, the device control unit 85 controls the refrigerant leakingcircuit into a stop state in the refrigerant leak third control. Inother words, the device control unit 85 stops the respective devices(the compressor 11, the heat-source-side fan 20, and the like) of therefrigerant circuit RC in which the refrigerant leak has occurred. Thisfurther reduces the inflow of the refrigerant into the refrigerantleaking circuit and reduces the further refrigerant leak.

The device control unit 85 does not stop the respective devices of therefrigerant circuits RC operating when the refrigerant leak detectionflag M6 is set and allows these devices to continue operating. In otherwords, in the refrigerant leak third control, the device control unit 85controls the refrigerant circuits RC, other than the refrigerant leakingcircuit out of the refrigerant circuits RC (device units R1) operatingwhen the refrigerant leak is detected, in the operating states. Thus,the refrigerant circuits RC in which no refrigerant leak is occurringcan continue operating.

(6-6) Drive Signal Output Unit 86

The drive signal output unit 86 outputs corresponding drive signals(drive voltages) to the respective devices (e.g., the devices 11, 13,16, 17, 20, 31, 32, 36, 46, 48) in accordance with details of control bythe device control unit 85. The drive signal output unit 86 includes aplurality of inverters (not illustrated) that output the drive signalsto specific devices (e.g., the compressor 11, the heat-source-side fan20, or the pump 36) corresponding thereto.

(6-7) Information Output Control Unit 87

The information output control unit 87 is a functional unit thatcontrols an operation of the output device 300. The information outputcontrol unit 87 causes the output device 300 to output predeterminedinformation in order that information on the operating state or thesituation may be output for the user. For example, the informationoutput control unit 87 causes the output device 300 to outputinformation (refrigerant leak notification information) for notifyingthat the refrigerant leak has occurred if the refrigerant leak detectionflag M6 is set. The refrigerant leak notification information is thedisplayed information such as letters or the sound information such asan alarm. Thus, a manager or the user can grasp the fact that therefrigerant leak has occurred and take a predetermined measure.

(7) Processing by Controller 80

With reference to FIG. 13, next, a description will be given ofexemplary processing to be performed by the controller 80. FIG. 13 is aflowchart of the exemplary processing to be performed by the controller80. When the power source is on, the controller 80 sequentially performssteps S101 to S110 illustrated in FIG. 13. The processing in FIG. 13 ismerely an example and may be changed as appropriate. For example, thesequence of the steps may be changed, some of the steps may be carriedout in parallel, or additional steps may be carried out insofar as thereare no inconsistencies.

In step S101, when the controller 80 assumes that the refrigerant leakhas occurred in the heat exchanger unit 30 (refrigerant circuits RC)(YES in S101), the processing proceeds to step S105. When the controller80 assumes that no refrigerant leak has occurred in the heat exchangerunit 30 (NO in S101), the processing proceeds to step S102.

In step S102, when no command ordering start of the operation (operationstart command) is input (NO in S102), the processing by the controller80 returns to step S101. On the other hand, when the operation startcommand is input (YES in S102), the processing by the controller 80proceeds to step S103.

In step S103, the controller 80 is placed in the normal operating mode(or kept in the normal operating mode). The processing then proceeds tostep S104.

In step S104, the controller 80 controls the states of the respectivedevices in real time in accordance with the input command, the settemperatures, and the detection values of the various sensors (S1, S2,and the like) to thereby cause the heat load processing system 100 toperform the forward cycle operation or the reverse cycle operation. Theprocessing then returns to step S101.

In step S105, the controller 80 is placed in the refrigerant leak mode.The processing by the controller 80 then proceeds to step S106.

In step S106, the controller 80 causes the output device 300 such as theremote controller to output the refrigerant leak notificationinformation. Thus, the manager can grasp the fact that the refrigerantleak has occurred. The processing by the controller 80 then proceeds tostep S107.

In step S107, the controller 80 performs the refrigerant leak firstcontrol. To put it concretely, the controller 80 has the exhaust fan 46and the cooling fan 48 driven with the predetermined numbers ofrotations (e.g., the maximum numbers of rotations). This, in the heatexchanger unit 30, facilitates the stirring or the discharge of theleaking refrigerant to thereby reduce the concentration of the leakingrefrigerant from locally becoming critically high. The processing by thecontroller 80 then proceeds to step S108.

In step S108, the controller 80 performs the refrigerant leak secondcontrol. Specifically, the controller 80 increases the ventilation airvolume (the air flow volume and/or the operating time per unit time) ofthe ventilation fan 210. As a result, the ventilation air volume by theventilation fan 210 increases to facilitate the discharge of the leakingrefrigerant to the outside space. Moreover, the device control unit 85switches the opening/closing mechanism 220 into the open state in therefrigerant leak second control. As a result, the facility device room Rcommunicates with the other space to facilitate the discharge of theleaking refrigerant in the facility device room R and further reduce thesituation that the concentration of the leaking refrigerant frombecoming locally high. The processing by the controller 80 then proceedsto step S109.

In step S109, the controller 80 performs the refrigerant leaking circuitidentification processing. To put it concretely, the controller 80controls the respective refrigerant circuits RC (respective device unitsR1) into the operating states and identifies the refrigerant leakingcircuit (refrigerant circuit RC in which the refrigerant leak isoccurring) based on any or all of the detection values of the respectiveheat-source-side sensors S1 and the respective heat exchanger unitsensors S2. The processing by the controller 80 then proceeds to stepS110.

In step S110, the controller 80 performs the refrigerant leak thirdcontrol. To put it concretely, the controller 80 controls the expansionvalve 31 and the on-off valve 32 of the refrigerant leaking circuit(refrigerant circuit RC in which the refrigerant leak has occurred) intothe closed states. This reduces the inflow of the refrigerant from theheat-source-side unit 10 into the refrigerant leaking circuit andreduces a further refrigerant leak in the heat exchanger unit 30. Thecontroller 80 controls the refrigerant leaking circuit into the stopstate in the refrigerant leak third control. In other words, the devicecontrol unit 85 stops the respective devices (the compressor 11, theheat-source-side fan 20, and the like) of the refrigerant circuit RC inwhich the refrigerant leak has occurred. This further reduces the inflowof the refrigerant into the refrigerant leaking circuit and reduces thefurther refrigerant leak. In the refrigerant leak third control, thecontroller 80 also controls the refrigerant circuits RC, other than therefrigerant leaking circuit out of the refrigerant circuits RC (deviceunits R1) operating when the refrigerant leak is detected, in theoperating states. Thus, the refrigerant circuits RC in which norefrigerant leak is occurring can continue operating. The processing bythe controller 80 then returns to step S101.

(8) Measures Against Refrigerant Leak in Heat Load Processing System 100

The heat load processing system 100 takes the following measures (i) to(iv) against the refrigerant leak.

(i)

The heat load processing system 100 includes therein the fans (theexhaust fan 46 and the cooling fan 48) disposed to generate the airflows (AF1, AF2) in the heat exchanger unit 30. When the refrigerantleak occurs in the heat exchanger unit 30, the refrigerant leak firstcontrol is performed to start the fans or increase the numbers ofrotations (the air flow volumes) of the fans. Thus, the leakingrefrigerant is stirred in the heat exchanger unit 30. Alternatively, theleaking refrigerant is discharged from the heat exchanger unit 30. As aresult, it is possible to reduce the hike in the concentration of theleaking refrigerant in the heat exchanger unit 30.

(ii)

In the heat load processing system 100, the controller 80 is configuredto control the ventilators 200 (the ventilation fan 210, theopening/closing mechanism 220) in the facility device room R where theheat exchanger unit 30 is installed. When the refrigerant leak occurs inthe heat exchanger unit 30, the refrigerant leak second control isperformed to increase the ventilation air volume by the ventilators 200.To put it concretely, the ventilation air volume (the air flow volume,the operating time per unit time) of the ventilation fan 210 isincreased. Moreover, the opening/closing mechanism 220 is switched intothe open state. As a result, the ventilation air volume in the heatexchanger unit 30 increases to facilitate the stirring and the dischargeof the leaking refrigerant in the facility device room R. As a result,it is possible to reduce the hike in the concentration of the leakingrefrigerant in the facility device room R.

(iii)

In the heat load processing system 100, when the refrigerant leak occursin the heat exchanger unit 30, the refrigerant leaking circuitidentification processing is performed. To put it concretely, in therefrigerant leaking circuit identification processing, the respectiverefrigerant circuits RC (respective device units R1) are controlled intothe operating states and the refrigerant leaking circuit (refrigerantcircuit RC in which the refrigerant leak is occurring) is identifiedbased on any or all of the detection values of the respectiveheat-source-side sensors S1 and the respective heat exchanger unitsensors S2. Thus, in the heat load processing system 100 including theplurality of refrigerant circuits RC (device units R1), it is possibleto quickly identify the refrigerant circuit RC in which the refrigerantleak is occurring.

In the heat load processing system 100, the expansion valves 31 and theon-off valves 32 that can switch between permission and interruption ofthe flows of the refrigerant from the heat-source-side units 10 to theheat exchanger unit 30 are disposed in the heat exchanger unit 30. Whenthe refrigerant leak occurs in the heat exchanger unit 30, therefrigerant leak third control is performed to switch the expansionvalve 31 and the on-off valve 32 in the refrigerant leaking circuit(refrigerant circuit RC in which the refrigerant leak has occurred) intothe closed states. This, as a result, interrupts the flow of therefrigerant from the heat-source-side unit 10 into the heat exchangerunit 30 to thereby reduce the further refrigerant leak.

Moreover, the refrigerant leaking circuit is controlled into the stopstate in the refrigerant leak third control. In other words, the heatload processing system 100 is configured to stop the respective devices(the compressor 11, the heat-source-side fan 20, and the like) of therefrigerant circuit RC in which the refrigerant leak has occurred. Thisfurther reduces the inflow of the refrigerant into the refrigerantleaking circuit and reduces the further refrigerant leak.

The respective devices of the refrigerant circuits RC operating when therefrigerant leak is detected are not stopped and are allowed to continueoperating in the refrigerant leak third control. In other words, theheat load processing system 100 is configured to control the refrigerantcircuits RC, other than the refrigerant leaking circuit out of therefrigerant circuits RC operating when the refrigerant leak is detected,in the operating states, in the refrigerant leak third control. Thus,the refrigerant circuits RC in which no refrigerant leak is occurringcan continue operating.

In this manner, the heat load processing system 100 is configured tochange the operating states of the respective refrigerant circuits RCbased on the result of the refrigerant leaking circuit identificationprocessing in the refrigerant leak third control.

(iv)

In the heat load processing system 100, the suction hole 47 a for thefirst air flow AF1 generated by the exhaust fan 46 is formed at thelower position than the uppermost portion A1 (the highest portion of therefrigerant pipes housed in the heat exchanger unit 30). Thisfacilitates the discharge of the refrigerant having a greater specificgravity than air from the heat exchanger unit 30 when such a refrigerantleaks in the heat exchanger unit 30. In other words, when therefrigerant having the greater specific gravity than air leaks in theheat exchanger unit 30, the leaking refrigerant accumulates in thebottom plate immediate upper space S1. However, since the suction hole47 a for the first air flow AF1 is formed at the lower position than theuppermost portion A1, discharge of the leaking refrigerant collecting inthe bottom plate immediate upper space S1 is facilitated.

(9) Features

(9-1)

In the foregoing embodiment, the casing 50 collectively houses theplurality of device units R1 forming the different refrigerant circuitsRC. The refrigerant leak detection unit (the refrigerant leak sensor 70,the refrigerant leak determination unit 84) individually detects therefrigerant leak in the respective device units R1 (i.e., the respectiverefrigerant circuits RC housed in the heat exchanger unit 30). When therefrigerant leak detection unit (the refrigerant leak sensor 70, therefrigerant leak determination unit 84) detects the refrigerant leak,the controller 80 is configured to perform the refrigerant leakingcircuit identification processing (first processing) for identify therefrigerant leaking circuit that is the refrigerant circuit RC in whichthe refrigerant leak is occurring and the refrigerant leak third control(second processing) for changing the operating state of thepredetermined refrigerant circuit RC based on the result of therefrigerant leaking circuit identification processing.

Thus, the heat load processing system 100 including the plurality ofrefrigerant circuits RC (specifically, including the plurality of deviceunits R1 in the same casing 50) can quickly identify the refrigerantcircuit RC in which the refrigerant leak is occurring. Moreover, it ispossible to change the operating state of the predetermined refrigerantcircuit RC according to the identification result.

(9-2)

In the foregoing embodiment, the controller 80 is configured to controlthe refrigerant leaking circuit into the stop state in the refrigerantleak third control (second processing). This reduces the furtherrefrigerant leak from the refrigerant leaking circuit when therefrigerant leak occurs.

(9-3)

In the foregoing embodiment, the controller 80 is configured to comparethe refrigerant states in the respective refrigerant circuits RC witheach other based on the detection values of the refrigerant statesensors (the heat-source-side sensors S1 and the heat exchanger unitsensors S2) to thereby identify the refrigerant leaking circuit in therefrigerant leaking circuit identification processing (firstprocessing). This makes it easy to discharge the leaking refrigerantfrom the facility device room to the other space when the refrigerantleak has occurred in the heat exchanger unit.

(9-4)

In the foregoing embodiment, the controller 80 is configured to identifythe refrigerant leaking circuit while operating the respectiverefrigerant circuits RC in the refrigerant leaking circuitidentification processing (first processing).

(9-5)

In the foregoing embodiment, the controller 80 is configured to controlthe refrigerant circuits RC, other than the refrigerant leaking circuitout of the refrigerant circuits RC operating when the refrigerant leakis detected by the refrigerant leak detection unit (the refrigerant leaksensor 70, the refrigerant leak determination unit 84), in the operatingstates, in the refrigerant leak third control (second processing). Thus,the refrigerant circuits RC in which no refrigerant leak is occurringcan continue operating.

(10) Modifications

The foregoing embodiment can be modified as appropriate as described inthe following modifications. Note that the respective modifications areapplicable in combination with other modifications insofar as noinconsistency arises.

(10-1) Modification 1

The heat exchanger unit 30 according to the foregoing embodiment may beformed as a heat exchanger unit 30 a illustrated in FIGS. 14 to 17. Theheat exchanger unit 30 a and a heat load processing system 100 aincluding the heat exchanger unit 30 a will be described below with afocus mainly on differences from the foregoing embodiment. Featuresshared with the foregoing embodiment will not be described unlessotherwise specified.

FIG. 14 is a perspective view of the heat exchanger unit 30 a. FIG. 15is a diagrammatic illustration showing a manner of disposition ofdevices in the heat exchanger unit 30 a in a plan view. FIG. 16 is adiagrammatic illustration showing the manner of disposition of thedevices in the heat exchanger unit 30 a seen from a right side. FIG. 17is a diagrammatic illustration showing the manner of disposition of thedevices in the heat exchanger unit 30 a in a front view. In FIG. 17, areference sign A1′ shows a highest portion (uppermost portion) ofrefrigerant pipes included in the heat exchanger unit 30 a and areference sign h1′ shows a height of the uppermost portion A1′. FIGS. 15to 17 show three refrigerant systems (refrigerant circuits RC) disposedin the heat exchanger unit 30 a, to which the ideas according to thepresent disclosure are not limited. In other words, the heat exchangerunit 30 a may include devices forming four or more refrigerant circuitsRC or devices forming less than three refrigerant circuits RC.

The heat exchanger unit 30 a has the devices included in theheat-source-side units 10. To put it more concretely, the heat exchangerunit 30 a has a substantially rectangular parallelepiped casing 51 andthe casing 51 houses the respective devices included in theheat-source-side units 10 in addition to the respective devices includedin the heat exchanger unit 30. In other words, in the heat exchangerunit 30 a, it can be said that the heat exchanger unit 30 and theheat-source-side units 10 are formed integrally. In other words, thecasing 51 collectively houses a device unit R1′ and other device unitsR1′. The device unit R1′ includes the first pipe P1 to the eleventh pipeP11, the compressor 11, the accumulator 12, the four-way switching valve13, a heat-source-side heat exchanger 14 a (second heat exchanger), thesubcooler 15, the heat-source-side first control valve 16, theheat-source-side second control valve 17, and the like in addition tothe refrigerant flow path RP of the first heat exchanger 34 or thesecond heat exchanger 35, the expansion valve 31, the on-off valve 32,and the refrigerant pipes Pa to Pd.

The heat exchanger unit 30 a has the heat-source-side heat exchanger 14a in place of the heat-source-side heat exchanger 14. While theheat-source-side heat exchanger 14 is configured to cause therefrigerant and the heat-source-side air flow to exchange heat with eachother, the heat-source-side heat exchanger 14 a is configured to causerefrigerant and heat-source-side heat medium (e.g., water) to exchangeheat with each other. The type of the heat-source-side heat exchanger 14a is not limited and the heat-source-side heat exchanger 14 a is adouble-pipe heat exchanger, for example. However, as theheat-source-side heat exchanger 14 a, it is only required toappropriately select a heat exchanger of the type usable for heatexchange between the refrigerant and the heat-source-side heat medium.The heat exchanger unit 30 a does not include the heat-source-side fan20 in relation to the fact that the heat exchange is performed betweenthe refrigerant and the heat-source-side heat medium (e.g., water). Inrelation to this, the heat load processing system 100 a may beconfigured as shown in FIG. 18, for example.

FIG. 18 is a schematic configuration diagram of the heat load processingsystem 100 a. In the heat load processing system 100 a, aheat-source-side heat medium circuit WC is formed. The heat-source-sideheat medium that exchanges heat with the refrigerant in each ofheat-source-side heat exchangers 14 a flows through the heat-source-sideheat medium circuit WC. The heat-source-side heat medium circuit WCincludes a cooling tower 90 that cools the heat-source-side heat mediumheated as a result of heat exchange with the refrigerant in each of theheat-source-side heat exchangers 14. The cooling tower 90 is installedon a rooftop, for example. The heat-source-side heat medium circuit WCincludes a plurality of heat-source-side pumps 92 for respectivelysending the heat-source-side medium to the heat-source-side heatexchangers 14, corresponding in number to the heat-source-side heatexchangers 14, and disposed in parallel.

The heat load processing system 100 a does not include the liquid-sideconnection pipes LP and the gas-side connection pipes GP in relation tothe fact that the heat load processing system 100 a has the respectivedevices included in the heat-source-side units 10.

In the heat load processing system 100 a, each of the heat-source-sideheat exchangers 14 a may heat the refrigerant by use of theheat-source-side heat medium. In this case, another device may bedisposed in addition to or as well as the cooling tower 90.

The heat load processing system 100 a can achieve similar functions andeffects to those of the foregoing embodiment (e.g., the functions andeffects in the foregoing (i) to (iv)) in a similar manner to the heatexchanger unit 30.

For example, when the controller 80 is configured to perform controlssimilar to the refrigerant leak first control, the refrigerant leaksecond control, the refrigerant leak third control, and the refrigerantleaking circuit identification processing, the heat load processingsystem 100 a exerts the similar functions and effects to those in theforegoing (i) to (iii).

In this case, the controller 80 may be configured to identify therefrigerant leaking circuit based on the detection values of any or allof the respective refrigerant state sensors (S1, S2) in the respectiverefrigerant circuits RC while controlling the expansion valves 31 andthe on-off valves 32 in the respective device units R1 into the closedstates and controlling the respective compressors 11 into the stopstates (i.e., controlling the respective refrigerant circuits RC intothe stop states) in the refrigerant leaking circuit identificationprocessing (first processing). In other words, because the heatexchanger unit 30 a collectively houses the heat-source-side devices, itmay be preferable to immediately stop the respective refrigerantcircuits RC when the refrigerant leak is detected in a situation where apump-down operation is not assumed to be very effective.

In this case, the controller 80 can easily identify the refrigerantleaking circuit, when the controller 80 is configured to identify therefrigerant leaking circuit based on a degree of a pressure drop of thehigh-pressure refrigerant in each of the refrigerant circuits RC(respective device units R1′) in the refrigerant leaking circuitidentification processing (first processing).

Moreover, if the exhaust fan unit 45 is provided such that the suctionhole 47 a for the first air flow AF1 is disposed at a lower positionthan the uppermost portion A1′ (the highest portion of the refrigerantpipes included in the heat exchanger unit 30 a), the heat loadprocessing system 100 a exerts the similar functions and effects tothose in the foregoing (iv).

The heat exchanger unit 30 a may include a second exhaust fan 46 a (seeFIG. 17) in place of or in addition to one or both of the exhaust fanunit 45 and the cooling fan 48. The second exhaust fan 46 a is disposednear the heat medium pipes (Ha to Hd) disposed in the heat exchangerunit 30 a. The second exhaust fan 46 a generates a third air flow AF3flowing from the heat exchanger unit 30 a to an outside (the facilitydevice room R). The second exhaust fan 46 a may be controlled in therefrigerant leak first control such that the second exhaust fan 46 ashifts into the operating state or the number of rotations (air flowvolume) of the second exhaust fan 46 a increases. When this secondexhaust fan 46 a is provided and controlled in the refrigerant leakfirst control, the heat load processing system 100 a can more noticeablyachieve the functions and effects in the foregoing (i). Especially,since the second exhaust fan 46 a is disposed near the heat medium pips(Ha to Hd), flowing of the leaking refrigerant into the living spaces SPvia the heat medium pipes Ha to Hd is reduced.

(10-2) Modification 2

All of the devices configuring the controller 80 (especially, the devicecontrol unit 85) in the foregoing embodiment may be disposed in theheat-source-side units 10 or the heat exchanger unit 30. In other words,the controller 80 (especially, the device control unit 85) may beconfigured by the heat-source-side control unit 29 or the heat exchangerunit control unit 49 only.

(10-3) Modification 3

Part or all of the devices configuring the controller 80 in theforegoing embodiment do not have to be disposed in the heat-source-sideunits 10 or the heat exchanger unit 30 and may be disposed in anotherplace. For example, part or all of the controller 80 may be disposed ina remote place in such a manner as to be able to communicate with thedevices controlled by the controller 80. In other words, part or all ofthe devices controlled by the controller 80 may be remote-controllable.

(10-4) Modification 4

The cooling fan 48 in the foregoing embodiment is not always necessaryand may be omitted as appropriate. In this case, the exhaust fan 46 inthe foregoing embodiment may function as the cooling fan 48. In otherwords, the exhaust fan 46 may be disposed such that the first air flowAF1 cools the heat generating components in the heat exchanger unitcontrol unit 49.

(10-5) Modification 5 In the foregoing embodiment, the controller 80 isconfigured to cause the ventilation fan 210 that is operatingintermittently to operate continuously in the refrigerant leak firstcontrol when the refrigerant leak is detected in the heat exchanger unit30. From a viewpoint of increasing the ventilation air volume in thefacility device room R, it is preferable to cause the ventilation fan210 to operate continuously. However, in the refrigerant leak firstcontrol, it is not always necessary to cause the ventilation fan 210 tooperate continuously insofar as the operating time per unit time of theventilation fan 210 is increased.

(10-6) Modification 6

In the foregoing embodiment, the suction hole 47 a for the first airflow AF1 is formed at the lower position than the lowermost portion A2(the lowest portion of the refrigerant pipes housed in the heatexchanger unit 30). However, the suction hole 47 a may be disposed at ahigher position than the lowermost portion A2 insofar as the suctionhole 47 a is disposed at a lower position than the uppermost portion A1(the highest portion of the refrigerant pipes housed in the heatexchanger unit 30).

(10-7) Modification 7

The one end (the suction hole 47 a) of the flow path forming member 47of the exhaust fan unit 45 may be connected to the discharge port 58 ain the bottom plate 58. In other words, the discharge port 58 a in thedrain pan may function as the suction hole 47 a for the first air flowAF1. In this case, the suction hole 47 a for the first air flow AF1 canbe said to be formed in the bottom plate 58 (drain pan).

(10-8) Modification 8

The numbers and manners of disposition of components disposed in theheat exchanger unit 30, e.g., the refrigerant pipes Pa to Pd, the heatmedium pipes Ha to Hd, the expansion valves 31, the on-off valves 32,the heat exchangers 33, and the pump 36 are not limited to the numbersand the manners of disposition shown as examples in the foregoingembodiment and can be changed as appropriate in accordance with theinstallation environment and the design specifications.

(10-9) Modification 9

In the foregoing embodiment, the heat exchangers 33 include the firstheat exchanger 34 and the second heat exchanger 35. However, this ismerely an example and the heat exchangers 33 may include three or moreheat exchangers. The heat exchanger 33 may be a single heat exchanger inwhich the same number of refrigerant flow paths RP as the refrigerantcircuits RC are formed, for example. The heat exchanger 33 may include aplurality of heat medium flow paths HP connected in parallel in the heatmedium circuit HC.

(10-10) Modification 10

The manners of configuration of the refrigerant circuits RC according tothe foregoing embodiment can be changed as appropriate in accordancewith the design specifications and the installation environment.Specifically, in each of the refrigerant circuits RC, other devices,e.g., a receiver and a valve may be disposed in place of or as well asthe devices shown in FIG. 1. Another expansion mechanism may be used inplace of each of the expansion valves 31 in the foregoing embodiment.For example, a mechanical expansion valve, a capillary tube, or the likemay be used in place of the expansion valve 31.

(10-11) Modification 11

In the foregoing embodiment, in relation to the fact that the pluralityof heat-source-side units 10 are arrange in parallel, the plurality of(here, four) refrigerant circuits RC are formed. In other words, in theheat load processing system 100, the plurality of refrigerant circuitsRC are formed by the plurality of heat-source-side units 10 and the heatexchanger unit 30. However, the number of the refrigerant circuits RCand the number of the heat-source-side units 10 do not necessarily haveto be the same. The number of the heat-source-side units 10 connected tothe heat exchanger unit 30 may be appropriately selected in accordancewith the installation environment and the design specifications.

(10-12) Modification 12

The heat load processing system 100 in the foregoing embodiment isconfigured to perform the forward cycle operation and the reverse cycleoperation. However, the heat load processing system 100 does not have tobe configured in this manner. In other words, the heat load processingsystem 100 may be configured as an apparatus that performs only one ofthe forward cycle operation and the reverse cycle operation. In thiscase, the four-way switching valve 13 may be omitted as appropriate.

(10-13) Modification 13

In the foregoing embodiment, the heat load processing system 100 is theair conditioning system that performs air conditioning of the livingspaces SP. However, the heat load processing system 100 does not have tobe the air conditioning system and may be other systems. For example,the heat load processing system 100 may be applied to a hot water supplysystem, a heat storage system, and the like.

In other words, the use-side units 60 are not limited to units forair-conditioning the living spaces SP and may be various kinds offacilities for cooling and/or heating processing machines or products byutilizing the heat medium cooled or heated by the heat exchanger unit30.

The use-side units 60 may be tanks for storing the heat medium cooled orheated by the heat exchanger unit 30. In this case, a pump or the like(not illustrated) sends the heat medium stored in the tank to devicesfor cooling and/or heating by utilizing the heat medium, for example.

(10-14) Modification 14

In the foregoing embodiment, the refrigerant leak sensor 70 is disposedin the bottom plate immediate upper space S1 in the heat exchanger unit30. However, a manner of disposition of the refrigerant leak sensor 70is not necessarily limited to this manner and may be changed asappropriate in accordance with the installation environment and thedesign specifications.

For example, the refrigerant leak sensor 70 may be disposed above thebottom plate immediate upper space S1 in the heat exchanger unit 30. Therefrigerant leak sensor 70 does not have to be disposed in the heatexchanger unit 30. For example, the refrigerant leak sensor 70 may bedisposed in a different device from the heat exchanger unit 30 ordisposed independently in the facility device room R.

(10-15) Modification 15

In the foregoing embodiment, the refrigerant leak sensor 70 is disposedin the heat exchanger unit 30 and the controller 80 (refrigerant leakdetermination unit 84) determines presence or absence of the refrigerantleak based on the signals sent from the refrigerant leak sensor 70.Thus, the presence or absence of the refrigerant leak in the heatexchanger unit 30 is detected. However, a manner of detection of therefrigerant leak is not necessarily limited to this manner and may bechanged as appropriate in accordance with the installation environmentand the design specifications.

For example, the controller 80 (refrigerant leak determination unit 84)may be configured to detect the presence or absence of the refrigerantleak in the heat exchanger unit 30 based on any of the detection valuesof the respective heat-source-side sensors S1 and/or the respective heatexchanger unit sensors S2. In this case, it is possible to omit therefrigerant leak sensor 70 as appropriate.

(10-16) Modification 16

In the foregoing embodiment, in the refrigerant leak second control,operations of the ventilation fan 210 and the opening/closing mechanism220 are controlled in such manners as to increase the ventilation airvolume by the ventilators 200 in the facility device room R. To achievethe effects in the foregoing (ii), it is preferable to perform therefrigerant leak second control in the manner as in the foregoingembodiment. However, in the refrigerant leak second control, it ispossible to control the operation of only one of the ventilation fan 210and the opening/closing mechanism 220. In this case, the ventilation airvolume in the facility device room R increases and therefore thefunctions and effects in the foregoing (ii) are still exerted.

(10-17) Modification 17

In the foregoing embodiment, in order to achieve the effects in theforegoing (i) and (ii), it is preferable to perform the refrigerant leakfirst control and the refrigerant leak second control as well as therefrigerant leak third control. However, the refrigerant leak firstcontrol and the refrigerant leak second control are not always necessaryfor the ideas according to the present disclosure and may be omitted asappropriate.

(10-18) Modification 18

It is possible to change the performing order of the refrigerant leakfirst control, the refrigerant leak second control, the refrigerant leakthird control, and the refrigerant leaking circuit identificationprocessing in the foregoing embodiment as appropriate. For example, itis possible to perform the refrigerant leaking circuit identificationprocessing and/or the refrigerant leak third control prior to therefrigerant leak first control and/or the refrigerant leak secondcontrol.

(10-19) Modification 19

In the foregoing embodiment, the casing 50 collectively houses the fourdevice units R1. However, it is possible to change the number of thedevice units R1 housed in the casing 50 as appropriate. The casing 50may house five or more device units R1 or three or fewer device unitsR1.

(10-20) Modification 20

In the foregoing embodiment, the controller 80 is configured to identifythe refrigerant leaking circuit while causing the respective refrigerantcircuits RC to operate in the refrigerant leaking circuit identificationprocessing (first processing). However, the refrigerant leaking circuitidentification processing is not necessarily limited to that describedin the foregoing embodiment and may be changed as appropriate accordingto the design specifications and the installation environment. Forexample, the controller 80 may be configured to perform the pump-downoperation for recovering the refrigerant into the heat-source-side units10 in the respective refrigerant circuits RC by causing the respectivecompressors 11 to operate after controlling the expansion valves 31 andthe on-off valves 32 of the respective device units R1 into the closedstates and identify the refrigerant leaking circuit based on thedetection values of any or all of the refrigerant state sensors (S1, S2)in the respective refrigerant circuits RC after the pump-down operationis completed in the refrigerant leaking circuit identificationprocessing (first processing).

Alternatively, for example, the controller 80 may be configured toidentify the refrigerant leaking circuit based on the detection valuesof any or all of the respective refrigerant state sensors (S1, S2) inthe respective refrigerant circuits RC while controlling the expansionvalves 31 and the on-off valves 32 in the respective device units R1into the closed states and controlling the respective compressors 11into the stop states (i.e., controlling the respective refrigerantcircuits RC into the stop states) in the refrigerant leaking circuitidentification processing (first processing).

(10-21) Modification 21

In the foregoing embodiment, when the refrigerant leak occurs in theheat exchanger unit 30, the controller 80 may stop the operation of thepump 36 in the refrigerant leak first control, the refrigerant leaksecond control, or the refrigerant leaking circuit identificationprocessing until the refrigerant leaking circuit is identified. Thisreduces flowing of the leaking refrigerant to the use-side units 60 (theliving spaces SP) via the heat medium circuits HC when the refrigerantleak has occurred in the heat exchangers 33.

(10-22) Modification 22

In the foregoing embodiment, the refrigerant leak third control by thecontroller 80 includes the following controls (a) to (c) for changingthe operating state of any of the refrigerant circuits RC based on theresult of the refrigerant leaking circuit identification processing.

(a) The controller 80 switches the expansion valve 31 and the on-offvalve 32 of the refrigerant leaking circuit (refrigerant circuit RC inwhich the refrigerant leak has occurred) into the closed states.

(b) The controller 80 controls the refrigerant leaking circuit into thestop state. In other words, the controller 80 stops the respectivedevices (the compressor 11, the heat-source-side fan 20, and the like)of the refrigerant circuit RC in which the refrigerant leak hasoccurred.

(c) The controller 80 does not stop the respective devices of therefrigerant circuits RC operating when the refrigerant leak is detectedand allows these devices to continue operating. In other words, thecontroller 80 controls the refrigerant circuits RC, other than therefrigerant leaking circuit out of the refrigerant circuits RC operatingwhen the refrigerant leak is detected, in the operating states, in therefrigerant leak third control.

It is preferable to perform all of the foregoing (a) to (c) in therefrigerant leak third control. However, it is not always necessary toperform all of the foregoing (a) to (c) insofar as at least one of theforegoing (a) to (c) is performed in the refrigerant third control. Inother words, in the refrigerant leak third control, it is possible toperform only one of the foregoing (a) to (c) insofar as the operatingstate of at least one of the refrigerant circuits RC is changed based onthe result of the refrigerant leaking circuit identification processing.

(11)

The embodiment has been described above. However, it should be construedthat various changes to modes and details will be available withoutdeparting from the gist and the scope recited in the claims.

INDUSTRIAL APPLICABILITY

The present disclosure can be used for a heat load processing system.

REFERENCE SIGNS LIST

-   -   10: heat-source-side unit    -   11: compressor    -   12: accumulator    -   13: four-way switching valve    -   14, 14 a: heat-source-side heat exchanger (second heat        exchanger)    -   15: subcooler    -   16: heat-source-side first control valve    -   17: heat-source-side second control valve    -   18: liquid-side shutoff valve    -   19: gas-side shutoff valve    -   20: heat-source-side fan    -   21-25: first temperature sensor to fifth temperature sensor        (refrigerant state sensors)    -   27: first pressure sensor (refrigerant state sensor)    -   28: second pressure sensor (refrigerant state sensor)    -   29: heat-source-side unit control unit    -   30, 30 a: heat exchanger unit    -   31: expansion valve    -   32: on-off valve    -   33: heat exchanger    -   34: first heat exchanger    -   35: second heat exchanger    -   36: pump    -   41: sixth temperature sensor (refrigerant state sensor)    -   42: seventh temperature sensor (refrigerant state sensor)    -   43: third pressure sensor (refrigerant state sensor)    -   44: fourth pressure sensor (refrigerant state sensor)    -   45: exhaust fan unit    -   46: exhaust fan    -   46 a: second exhaust fan    -   47: flow path forming member    -   47 a: suction hole    -   48: cooling fan    -   49: heat exchanger unit control unit    -   50: casing    -   50 a: discharge hole    -   51: casing    -   55: electric component box    -   58: bottom plate    -   58 a: discharge port    -   60: use-side unit    -   70: refrigerant leak sensor (refrigerant leak detection unit)    -   80: controller (control unit)    -   80 a, 80 b: adaptor    -   81: storage unit    -   82: input control unit    -   83: mode control unit    -   84: refrigerant leak determination unit (refrigerant leak        detection unit)    -   85: device control unit (control unit)    -   86: drive signal output unit    -   87: information output control unit    -   90: cooling tower    -   92: heat-source-side pump    -   100, 100 a: heat load processing system    -   200: ventilator    -   210: ventilation fan    -   220: opening/closing mechanism    -   300: output device    -   581: bottom face portion    -   A1, A1′: uppermost portion    -   A2: lowermost portion    -   AF1: first air flow    -   AF2: second air flow    -   AF3: third air flow    -   B1: building    -   D: ventilation duct    -   GP: gas-side connection pipe    -   H1: first heat medium connection pipe    -   H2: second heat medium connection pipe    -   HC: heat medium circuit    -   HP: heat medium flow path    -   Ha-Hd: heat medium pipe    -   LP: liquid-side connection pipe    -   P1-P11: first pipe to eleventh pipe    -   Pa, Pb, Pc, Pd: refrigerant pipe    -   R: facility device room    -   R1, R1′: device unit (refrigerant system component device)    -   RC: refrigerant circuit (refrigerant system)    -   RP: refrigerant flow path    -   S1: heat-source-side sensor (refrigerant state sensor)    -   S2: heat exchanger unit sensor (refrigerant state sensor)    -   SP: living space    -   Sa: lower space    -   Sb: upper space    -   S1: bottom plate immediate upper space    -   WC: heat-source-side heat medium circuit

CITATION LIST Patent Literature

-   Patent Literature 1: JP 2006-38323 A

1. A heat load processing system including a plurality of refrigerantsystems through which refrigerant circulates, the system comprising: aplurality of refrigerant system component devices including a compressorthat is configured to compress the refrigerant and/or a heat exchangerthat is connected to a refrigerant pipe through which the refrigerantflows and a heat medium pipe through which heat medium flows and beingconfigured to cause the refrigerant and the heat medium to exchange heatwith each other, as devices configuring one of the refrigerant system; acasing collectively housing the plurality of refrigerant systemcomponent devices configuring the different refrigerant systems; arefrigerant leak detector configured to individually detect arefrigerant leak in the respective refrigerant systems; and a controllerconfigured to control operations of actuators of the respectiverefrigerant systems, the controller being configured to perform, whenthe refrigerant leak detector detects the refrigerant leak, firstprocessing for identifying a refrigerant leaking system that is therefrigerant system in which the refrigerant leak is occurring and secondprocessing for changing an operating state of at least one of therefrigerant systems based on a result of the first processing.
 2. Theheat load processing system according to claim 1, wherein the controlleris configured to control the refrigerant leaking system into a stopstate in the second processing.
 3. The heat load processing systemaccording to claim 1 further comprising a refrigerant state sensorconfigured to detect pressures or temperatures of the refrigerant in therespective refrigerant systems, wherein the controller is configured toidentify the refrigerant leaking system by comparing states of therefrigerant in the respective refrigerant systems with each other basedon detection value of the refrigerant state sensor in the firstprocessing.
 4. The heat load processing system according to claim 1,wherein the controller is configured to identify the refrigerant leakingsystem while operating the respective refrigerant systems in the firstprocessing.
 5. The heat load processing system according to claim 1,wherein the controller is configured to identify the refrigerant leakingsystem while stopping the respective refrigerant systems in the firstprocessing.
 6. The heat load processing system according to claim 5,wherein the refrigerant system component devices further include asecond heat exchanger that is configured to cause the refrigerantcompressed by the compressor to condense or radiate heat by causing therefrigerant to exchange heat with water, and the controller isconfigured to identify the refrigerant leaking system based on a degreeof a pressure drop of high-pressure refrigerant in each of therefrigerant systems in the first processing.
 7. The heat load processingsystem according to claim 1, wherein the controller is configured tocontrol the refrigerant systems, other than the refrigerant leakingsystem out of the refrigerant systems operating when the refrigerantleak is detected by the refrigerant leak detector, in operating states,in the second processing.
 8. The heat load processing system accordingto claim 2 further comprising a refrigerant state sensor configured todetect pressures or temperatures of the refrigerant in the respectiverefrigerant systems, wherein the controller is configured to identifythe refrigerant leaking system by comparing states of the refrigerant inthe respective refrigerant systems with each other based on detectionvalue of the refrigerant state sensor in the first processing.
 9. Theheat load processing system according to claim 2, wherein the controlleris configured to identify the refrigerant leaking system while operatingthe respective refrigerant systems in the first processing.
 10. The heatload processing system according to claim 3, wherein the controller isconfigured to identify the refrigerant leaking system while operatingthe respective refrigerant systems in the first processing.
 11. The heatload processing system according to claim 2, wherein the controller isconfigured to identify the refrigerant leaking system while stopping therespective refrigerant systems in the first processing.
 12. The heatload processing system according to claim 3, wherein the controller isconfigured to identify the refrigerant leaking system while stopping therespective refrigerant systems in the first processing.
 13. The heatload processing system according to claim 2, wherein the controller isconfigured to control the refrigerant systems, other than therefrigerant leaking system out of the refrigerant systems operating whenthe refrigerant leak is detected by the refrigerant leak detector, inoperating states, in the second processing.
 14. The heat load processingsystem according to claim 3, wherein the controller is configured tocontrol the refrigerant systems, other than the refrigerant leakingsystem out of the refrigerant systems operating when the refrigerantleak is detected by the refrigerant leak detector, in operating states,in the second processing.
 15. The heat load processing system accordingto claim 4, wherein the controller is configured to control therefrigerant systems, other than the refrigerant leaking system out ofthe refrigerant systems operating when the refrigerant leak is detectedby the refrigerant leak detector, in operating states, in the secondprocessing.
 16. The heat load processing system according to claim 5,wherein the controller is configured to control the refrigerant systems,other than the refrigerant leaking system out of the refrigerant systemsoperating when the refrigerant leak is detected by the refrigerant leakdetector, in operating states, in the second processing.
 17. The heatload processing system according to claim 6, wherein the controller isconfigured to control the refrigerant systems, other than therefrigerant leaking system out of the refrigerant systems operating whenthe refrigerant leak is detected by the refrigerant leak detector, inoperating states, in the second processing.